Unwrap and freeze 12 Cadbury Eggs. It is easier to unwrap them before than after freezing.
Prepare boxed cake mix according to package directions or make your own homemade cake mix. Preheat oven according to package directions.
Line cupcake pan with extra large muffin liners. Fill each half way with cake batter and then a frozen egg.
Spoon another small amount of cake batter over the top of each to coat.
Bake according to package directions. Due to the centers being hollow with Cadbury Eggs you won't need to bake for longer even though the overall cupcake is larger. Remove when tops are lightly browned and spring back when touched. Due to the center being filled, a toothpick test will not be an accurate indicator.
Allow cupcakes to cool completely.
Beat together the butter and shortening until well combined and frothy.
Add the powdered sugar, vanilla, salt and milk. Mix for 2-3 minutes or until light and fluffy.
Scoop Cadbury creme filling from 6 of the eggs, gently and by hand, fold in creme filling. It should only take 2-3 strokes to get thick streaks.
Frost generously with an offset spatula or filling a frosting bag with frosting and using a large 1A round tip, frost cupcakes.
Using a sharp knife, split the remaining 6 eggs in half. Top each cupcake a Cadbury Egg halve.
If you've tried this recipe come back to let us know how it was in the comments or ratings.
You can use regular vanilla extract, but clear will keep the frosting a fluffy white. If you use salted butter, omit additional salt.