CUPCAKES: Preheat oven to 350-degrees. Line a mini cupcake tin with twelve mini cupcake liners and set aside.

In the bowl of a stand mixer, affixed with the paddle attachment, add the egg, white sugar and brown sugar, and mix on high speed for 6-8 minutes. Turn mixer off and scrape down the sides of the bowl.

In a medium sized bowl, add the flour, baking powder, baking soda, salt and nutmeg. Stir until combined. Turn mixer to low and add half of the dry ingredients into the sugar mixture, alternating with the mayonnaise, and continuing until the dry ingredients and mayonnaise have all been added into the mixer. Mix until combined.

Remove the bowl from the mixer and stir in the water and vanilla extract. Stir until ingredients are completely combined and batter is smooth. Fill cupcake liners half full with batter and bake in 350-degree oven for 10 minutes, or until a toothpick inserted into the middle comes out without wet batter on it.

Remove baked cupcakes from the oven and as soon as the cupcakes are cool enough to handle, remove the cupcakes from the tin and place on a wire rack to cool completely before frosting.

FROSTING: Cut COLD butter into pieces. Using the paddle attachment on an electric mixer, whip the butter for 5-minutes, scraping down the sides of the bowl as needed. Beat the butter until it is pale in color.

Add two cups of the powdered sugar to the mixer, and mix on low until incorporated into the butter.

Add one teaspoon of vanilla extract to the mixer and mix until combined.

Add the last cup of powdered sugar, heavy whipping cream, salt and last teaspoon of vanilla extract to the mixer. Add the food coloring if using. Beat on low until the ingredients are incorporated. Increase the speed of the mixer to medium-high and beat for another 5 minutes.

Frost onto cooled cupcakes.