Prepare your vanilla cupcakes.
As the cupcakes cool, prepare the bunny toppings. Cut each regular-sized marshmallow in half, lengthwise. Line up the marshmallow halves on wax paper, bottom side up.
In a large bowl, mix together softened butter, confectioners’ sugar and milk with an electric or stand mixer. Start on low and increase to high to get it fully whipped and blended thoroughly.
Scoop a ¼ cup of the buttercream into a separate bowl and tint with one small drop of pink gel food coloring. Scoop pink buttercream into a piping bag with Wilton tip #5 attached. Frost 3 small circles on the bottom of each marshmallow, followed by a large oval on top.
Scoop the remaining un-tinted buttercream into another piping bag with Wilton tip #12 attached and frost each cupcake in a circular pattern.
Place one mini marshmallow at the top of each cupcake to represent the bunny’s “tail” while placing two “bunny feet” on each cupcake at the bottom, angling slightly outward. Repeat for each cupcake until they’re all decorated with a “tail” and “two feet” on each!
Repeat with all cupcakes! Serve and enjoy!