Story highlights Fans of Cadbury Creme Eggs are upset about a recipe change

Cadbury Creme Eggs appear on shelves from January until Easter

American food giant Kraft acquired British-based Cadbury in 2010

(CNN) The makers of Cadbury Creme Eggs are walking on eggshells with fans of the beloved Easter treat after a recent tweak in the recipe.

The chocolate eggs, filled with a cloying "yolk" of yellow and white fondant, were originally made in the United Kingdom with Cadbury's signature Dairy Milk chocolate.

Now, under the new recipe, they're made with "a standard, traditional Cadbury milk chocolate," said a spokeswoman for Mondelez International, a spinoff of Kraft Foods, in a statement. Kraft acquired British candy maker Cadbury in 2010 for roughly $19 billion.

The change applies only to Cadbury eggs sold in the United Kingdom. The goo-filled eggs usually appear on shelves starting in January until April.

"We have always used a range of milk chocolate blends for different products, depending on their shape or consistency," the spokeswoman said. "The fundamentals of the Cadbury Crème Egg remain exactly the same -- delicious milk chocolate and the unique creme centre that consumers love."

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