Preheat the oven to 350 degrees. Line cupcake pans with 24 cupcake liners and set aside.
Add the butter and sugar to a bowl and mix on high for 5 minutes until the mixture is light and fluffy.
Add in the vanilla and eggs and mix.
Mix in the sour cream.
Add in the baking soda and powder, and flour and mix until just combined. Be careful not to over mix.
Divide the batter between 3 bowls.
Add one of the powders to each bowl, creating three different colors. Mix to combine.
Add a scoop of each color to each cupcake tin. You will need about 1 1/2 tbsp of each color.
Bake for 25-30 minutes or until a toothpick comes out clean.
Allow to completely cool before frosting.
Swiss Meringue
Whisk the egg whites and sugar in a glass bowl for 5 minutes.
Transfer the bowl to a simmering pot of water over medium-low heat, creating a double boiler. Make sure the water never touches the bottom of the bowl.
Whisk for 5-8 minutes until the mixture becomes frothy and the temperature is 160 degrees.
Transfer the mixture to a mixing bowl and mix on high for 10 minutes. It should become thick, luscious, and hold its shape in stiff peaks.