Preheat oven to 350 degrees.
Line a muffin tin with cupcake liners. This recipe will make 6 large cupcakes or 24 small. In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.
In a large bowl with a hand mixer, combine the melted butter and the sugar together.
Add the egg whites, mayonnaise, milk, and the vanilla and combine.
Slowly incorporate the dry ingredients into the wet ingredients and continue to mix until the batter is smooth.
Divide the batter among the cupcake wells.
Bake for 18 to 20 minutes or until a toothpick inserted in the center comes out clean.
Cool completely.
Carefully form little nests of cotton candy and place them on top of each cupcake.
Place 3 eggs into each nest.
NOTE: Decorate just prior to serving. Cotton candy can melt and dissolve depending on your weather and humidity.