When you think "All-American" you may think "apple pie." Well, sorry to be the bearer of bad news, but you're wrong. Chocolate-chip cookies are the essential American baked good. Apple pie dates back to the medieval times (just see the article over at Gode Cookery , the infringing of which started the internet firestorm against Cooks Source magazine). Chocolate-chip cookies are a true American ( accidental ) invention.The Nestle Toll House recipe, found on the back of Nestle chocolate chip packages, is based on Ruth Wakefield's original recipe. This recipe is a good starting-off point, and a classic go-to when you're in a pinch. I adapted mine based on info from a New York Times article , in which it was revealed that Wakefield's recipe called for chilling the dough overnight, as well as a bit of my foray into experimenting with baking science (see notes at end of recipe).10 minutes1.25 hrs (plus 12-36 hours to chill the dough)15 large cookies2.25 c flour1.5 tsp table salt0.5 tsp baking soda0.5 tsp baking powder0.5 lb unsalted butter, melted1 c brown sugar0.5 c granulated sugar2 tsp vanilla2 large eggs, room temperature6 oz 70% cacao baking chunks 1 tsp kosher or sea salt(1) Mix the sugars with the melted butter and vanilla until combined(2) Mix in eggs, one at a time(3) In a separate bowl, mix the flour, table salt, baking soda, and baking powder(4) Add flour mixture to butter mixture, slowly, just until combined(5) Fold in chocolate chips(6) Cover and refrigerate for 12-36 hours(7) Remove from refrigerator and let sit for 20 minutes, until dough is pliable(8) Preheat oven to 350 degrees(9) Roll dough into balls, just larger than a golf ball, packing the dough in tightly(10) Place cookies on parchment-paper lined baking sheet, with at least 2" around each cookie(11) Sprinkle a few flakes of kosher salt on top of each cookie ball(12) Bake for 12 minutes(13) Remove cookie sheet from oven, and let sit for 5 minutes(14) Move parchment paper to a wire rack to cool(15) Enjoy the deliciousnessNotes: The cookies will seem underbaked - this is necessary to maintain a chewy texture. The edges will be just browning, the top will be cracking, and the dough in the cracks will seem moist. As they cool, moisture is evaporated and they will set into perfectly chewy cookie. If you bake them until they appear "done" they will end up crispy when cooled.The science of the cookies: My first recipe resulted in cookies with too much spread, so they were thin and crispy. This basically meant that the dough lacked the right amount of leavening agents.Here is how I tweaked it, and why that changed the result:(a) Melting the butter. When heated, any undissolved sugar crystals melt, causing the cookies to spread more. Dissolving the sugar into the melted butter corrects this problem.(b) Replace some of the granulated sugar with brown sugar. Same reason as melting the butter - brown sugar dissolves more readily than granulated. You could also use caster sugar (c) Baking powder. Baking soda creates CO2 (and thus the dough rises), when it reacts with acidic ingredients in the dough (such as brown sugar). Baking powder is baking soda mixed with an acidic ingredient, so it will rise without the need for acid in the dough. Adding more brown sugar provides more acid with which the baking soda can react; baking powder will cause the dough to rise even more. Basically, we give the dough its maximum rising potential. Also, if the dough is more alkaline (meaning too much unused baking soda), the gluten fibers in the flour will develop more and thus be longer (meaning more spread).(d) Chilling the dough. Besides the fact that chilled dough tastes better than unchilled, there is a scientific reason for the difference. In order for an even texture and flavor to develop, the moisture in the dough needs to be evenly distributed. One way to do this is to mix the dough thoroughly. Overmixing, however, over-develops the gluten, which results in tough, unpleasant cookies.If, instead, you chill the dough, the moisture can distribute evenly without the problem of over-developingthe gluten.