Ina small pot over medium heat, combine white rabbit candy and milk. The candy will slowly melt and turn the mixture syrupy. Keep on stirring with a rubber spatula until all the candy has fully melted. Once the candy has all melted, set mixture aside and let cool.
Inthe bowl of a mixer, beat butter until light and fluffy. Add icing sugar, one cup at a time, and mix until fully incorporated. Add vanilla and cooled white rabbit candy syrup.
Continue beating buttercream on high speed until fluffy, 3 - 5 minutes.
Transfer buttercream to a piping bag fitted with a piping tip and decorate away.
Instructions
Vanilla Cupcakes
Preheat oven to 350F and line a cupcake pan.
In a bowl of a mixer, beat butter and sugar until smooth. Add egg and mix until incorporated.
In a medium-sized bowl, whisk to combine flour, cornstarch, baking powder, baking soda, and salt. Set aside.
In a measuring cup, combine sour cream, vegetable oil, vanilla extract, and milk.
Add the dry ingredients the butter mixture and while the mixer is running on low, slowly add the milk mixture. Mix until combined.
Fill cupcake liners 3/4 way full and bake for 14 - 16 minutes. They are done when they are lightly golden brown and when a toothpick comes out without wet batter stuck to it.