From crullers to Long Johns, the seven fried-dough varieties that changed breakfast forever.

It’s a late Sunday morning, and a hungover punk kid with a comb stuck in his hair is standing behind a woman whose distressed jeans are a little too expensive for this part of town. A couple who arrived by bicycle wait inside the front door — this space isn’t built for crowds, though it draws them — and a mother who walked over hand-in-hand with two children struggles to keep the kids from running up and down the sidewalk. Outside at the street corner, a guy in Ray-Bans plays with his French bulldog while his girlfriend finds a spot in line and pulls out her iPhone, bracing for a long wait. The shop drawing crowds is Dough, a sweet-scented beacon in this otherwise gritty part of town. The projects are just across the street, but tourists and New Yorkers flock to where Franklin meets Lafayette in Brooklyn, waiting in line just to get a doughnut.

Doughnut shops across America, whether they’re in Secaucus, St. Louis, or San Diego, attract a diverse clientele. The doughnut, at times a symbol of ease, excess, or earnestness, qualifies characters throughout pop culture, from daft everyman Homer Simpson to Twin Peaks’ clever Agent Dale Cooper to sly serial killer Dexter Morgan (Dexter). But how did the circular fritter become a symbol of Americana?

In the newly published Oxford Companion to Sugar and Sweets, food writer Michael Krondl tackles the confusing history of the doughnut. The first reference to a fried dough, a honey-glazed sweet fried in olive oil, comes from Athenaeus in the third century C.E. The American doughnut can trace its origins to 1750. The Country Housewife ’ s Family Companion contains a recipe for a sweet fried fritter; by 1802, a recipe for a "Dough Nut" appeared in the book The Frugal Housewife. The now-standard doughnut’s hole is still up for debate. Krondl surmises that the shape came from recipes that called for the dough to be shaped like a jumble — a once common ring-shaped cookie. In Cuisine and Culture: A History of Food and People, culinary historian Linda Civitello writes that the hole was invented because it allowed the doughnuts to cook faster. By 1870 doughnut cutters shaped in two concentric circles, one smaller than the other, began to appear in home-shopping catalogues.

Until the early 1800s, homemade doughnuts were yeast-risen and time-consuming to produce. It wasn’t until 1829 — when chemical leaveners like pearlash, a precursor to baking powder, became widely available — that quicker, chemically-raised cake doughnuts showed up in American households. By the early 1900s, doughnuts were a common snack across the country. World Wars I and II helped cement the doughnut’s image as a wholesome American creation: The Salvation Army and Red Cross served doughnuts to the front lines. In War Through the Hole of the Doughnut, writer Andrew Pipanne notes that the servicewomen who served soldiers fresh fritters were known as Doughnut Dollies. After World War II ended, veterans opened some of the first doughnut shops on American soil. The American doughnut persists as a working-class breakfast and afternoon snack, cop-and-doughnut trope notwithstanding.

At its most basic, the American doughnut is made from dough that is mixed, shaped, and fried. Depending upon the type of leavening agent, it may be kneaded and require time to rise before cooking. Unlike fried fritters in Asia or South America, the American doughnut is a sweet snack; after its time in the fryer, it is generally dipped in a dry or wet sugar mixture. It may also be glazed with chocolate or filled with a fruit jam, custard, or cream. Here now, the seven types of American doughnuts and where to find excellent specimens of each style.

Yeast

Most doughnuts at shops across America are yeast-risen doughnuts. The base dough — which typically contains flour, sugar, salt, yeast, water or milk, sometimes eggs, and sometimes butter or oil — is mixed, sometimes kneaded, and then allowed to rise for several hours (or overnight). It is then rolled, cut, and allowed to rise again before each pre-shaped ring is dropped gently into hot oil. The finished fried dough rings are characterized by a fluffy texture and thin, soft, golden-brown crust. They range from impossibly light and airy confections to dense, bread-like pillows. They may contain cornstarch or potato starch in addition to wheat flour, an addition that yields a more airy interior.

Where to eat them:

· Krispy Kreme didn’t invent the doughnut, but thanks to some high-tech food science, it’s created what is arguably the best mass-market fritter on the market today. Its original glazed doughnut, when served hot from the fryer, weighs just over an ounce. There are 37 ingredients in the doughnut, including soy and barley flours, cornstarch, and three types of sugar, so it’s not great for the human body — but it does have a very particular, very weightless quality atop the tongue.

· Southern California’s Sidecar Doughnuts & Coffee promises to serve the freshest doughnut in the country: The shop actually throws out its entire stock of doughnuts every two hours. Though fans go crazy over the maple bacon bars, cinnamon crunch, and strawberry doughnuts, it’s the shop’s simple vanilla twist that is most worth a stop. Always fresh, fluffy, never greasy, and coated with a parchment-thin vanilla bean glaze, it’s the ne plus ultra of yeast doughnuts.

· The Doughnut Vault in Chicago makes excellent (though somewhat large) yeasted doughnuts. In the winter, when the cold, angry wind blows through the streets downtown, a line snakes outside the shop and customers emerge, a cup of steaming coffee in one fist and a glazed chestnut round, still plump from the fryer, in the other.

Cake

Unlike the yeasted doughnut, the cake doughnut’s leavening agent is chemical (baking soda, baking powder) rather than biological (yeast). This means the base mixture — a blend of flour, milk or water, salt, sugar, sometimes eggs, and either baking soda or baking powder — doesn’t require time to rise, and can be mixed, shaped, and fried immediately. Cake doughnuts are generally prepared as a batter, though they can also be prepared as dough. If prepared as a dough, they may be rolled and shaped into a ring, or rolled flat and cut out into the desired shape. If they are prepared as batter, they must be dropped carefully, usually from a special contraption, into the hot oil.

Cake doughnuts cook rather quickly, but absorb more oil than yeasted doughnuts. The finished doughnut is crumbly and dense, with a crisp exterior. It’s a doughnut made for dunking: into hot coffee, if you’re Agent Cooper in Twin Peaks. The related cider doughnut is simply a cake doughnut made with the addition of apple cider as a liquid rather than just water or milk. They are almost always dipped in cinnamon sugar after they’re fried.

Where to eat them:

· Federal Donuts, the fried chicken institution with several locations in Philly, makes a cake doughnut many swoon after. It comes in almost a dozen different flavors, depending upon the day, including cookies and cream, Indian cinnamon, vanilla-lavender, milk chocolate-sea salt, sticky bun, and honey. Chef Michael Solomonov’s cake doughnut base mixture is standard save the addition of baharat, a Middle Eastern blend of brown spices which usually includes allspice and clove.

· St. Louis’s Donut Stop has been serving the city since 1953. It makes three main types of cake doughnuts — vanilla, Devil’s Food, and blueberry — and its cake doughnut recipes haven’t changed over the years. The shop serves the doughnuts plain, iced, glazed, or sugared depending upon the day and the order, but it’s the texture that sets this shop apart from the others. The cake doughnuts come out lighter and with a crisper crust than most others. Cake doughnut holes are also on offer at both St. Louis-area locations.

Jelly

Krapfen, paczki, sufganiyah, berliner, bismark: These are all the name for a round doughnut filled with fruit jam. Jelly doughnuts are most often made from yeasted dough that’s cut either into squares or rounds, and then filled after being fried. Strawberry and raspberry are common jelly doughnut flavors, but chains across the country use every kind of preserve, curd, and fruit butter imaginable.

A cousin of the jelly doughnut is the straightforward fruit-filled doughnut, usually split and then filled with a fresh-fruit or pie-like compote.

Where to eat them:

· Portland-based Voodoo Doughnut is best known for its over-the-top creations, but the chain offers a standard round jelly doughnut at its Oregon shops, filled with a seasonal and ever-changing variety of jam from Kelly’s Jelly, a local jam maker. When Voodoo fills fried rounds with Kelly’s Jelly’s marionberry preserves, it's a good day.

· In Tucson, locals line up for the house-made lemon curd-filled bismarks at Le Cave’s Bakery.

· At Revolution Doughnuts & Coffee in Atlanta, sugar-dusted rounds are filled with blackberry jam, passion fruit curd, or even freshly stewed figs, depending upon the day.

Cream

A cream doughnut is simply a cake or yeasted doughnut filled with cream, which is typically a pastry cream (thickened with eggs) or American pudding (thickened with cornstarch) and often vanilla, chocolate, lemon, or coconut-flavored. The best varieties are filled fresh or to-order with house-made custards lightened a bit with whipped cream.

Where to eat them:

· At Doughnut Plant in New York City, the crème brûlée doughnut takes cream-filled fritters out of the realm of breakfast and into the realm of dessert. Vanilla pudding fills these rounds before they get the ultimate finish: a layer of burnished sugar which crackles when you bite into the doughnut.

· In the summer, San Diego’s Donut Bar makes a hybrid jelly/cream creation called a peach split in which a round yeasted doughnut is split and then filled with fresh diced peaches and whipped cream.

Old-Fashioned

The old-fashioned doughnut is the jolie laide ring of dough that’s cousin to the cake doughnut. It’s risen with a chemical leavener and made into either batter or dough. It's fried at a lower temperature than other doughnuts, thereby creating a craggy, rough-edged specimen. Glaze clings to its cracks; it begs to be dipped into milk or a cup of joe.

Where to eat them:

· Top Pot Hand-Forged Doughnuts & Coffee is a Seattle-based institution that makes a picture-perfect old-fashioned. Available as a vanilla or chocolate base, it’s served plain or dipped in glaze, raspberry glaze, chocolate icing, maple icing, or sugared pumpkin (in season). The doughnut is crispy on the edges but gives way to a soft, cakey interior.

· Fox’s Donut Den in Nashville serves an old-fashioned so crisp, it’s all-flaky exterior with almost no bread-y interior — more like a fritter than a doughy doughnut in the best way.

Cruller

Originally a Dutch creation, the cruller (or kruller) is made from a rectangle of yeasted dough that is slit in the middle so it can be twisted and folded upon itself and then fried. While German and Eastern European bakeries still sometimes sell krullers, the version commonly found at American doughnut shops is shaped into a round and, in a confusing twist (pun intended), called a French cruller.

Sources disagree about the French cruller’s evolution, but it’s clear that the modern interpretation is based upon French choux pastry — an eggy batter typically used to make cream puffs and eclairs. Unlike cake and yeasted doughnuts, the French cruller gets its rise from a mechanical leavening agent: In this case, the dough incorporates beaten eggs which, when cooked, puff and expand. When fried instead of baked, the batter retains its airiness and if piped into hot oil from a pastry bag fitted with a fluted tip, the finished product resembles a ridged ring.

However, most French crullers today — though made from a batter that is eggier than both cake and yeasted doughnuts — are fluted, ring-shaped fritters not because of any special piping technique. They’re mass-produced and a result of an industrial extruding nozzle which mimics the confections' original ridges. Dunkin’ Donuts’s cruller — the most widely available example — is now considered the standard American doughnut shop version of the French cruller.

It may as well be noted that Spanish churros are made from a similarly egg-rich batter, but are usually piped into the hot oil in long sticks or very large concentric circles and served always dusted with sugar. The American French cruller is almost always glazed.

Where to eat them:

· Plan Check, a restaurant with several locations in Los Angeles, makes a single dessert: giant crullers fried to order, dusted with cinnamon sugar, and served with whipped cream and sliced bananas or strawberries. The eggy batter produces extremely light fritters with an extra-crisp crust.

· At Peter Pan Donut & Pastry Shop in Brooklyn’s Greenpoint neighborhood, the crullers are just one of many varieties on offer. They also come glazed in chocolate.

Long John

The American Long John doughnut is a yeasted doughnut cut into a rectangle. Its oblong shape is sometimes, in the U.S., called an eclair or an eclair doughnut, after the (baked, not fried) French pastry. Some shops call the rectangular fritter an eclair when filled and a Long John when unfilled; other shops do not make a distinction, which leads to some confusion. When glazed with a maple-flavored glaze, a Long John is known as a maple bar. Several West Coast-based chains top their maple bars with bacon and call them maple bacon bars.

Where to eat them:· Bob’s Coffee & Donuts in L.A. has been serving fritters of every shape and size since 1947. They offer both a cream-filled Long John and a simply glazed maple bar.

· Chicago’s mini doughnut chain Glazed & Infused always stocks maple bacon bars. Unfilled, the combination of chewy fried dough, sticky sweet maple glaze, and salty caramelized bacon can be overwhelming — or the ideal hangover cure.