Preheat oven to 350 degrees.
Start by creaming 10 tablespoon of softened butter together with 1 ½ cups of granulated sugar.
Then add in 4 egg whites along with 1 tablespoon of vanilla bean paste and mix for two minutes until it is paler and color and slightly fluffy.
In a small bowl sift together 2 ¼ cups of cake flour, 1 ½ teaspoon of baking powder, ¼ teaspoon of baking soda and ½ teaspoon of salt.
Alternate adding 1 cup of buttermilk and the dry ingredients to the butter/sugar/egg mixture. Mix until everything is incorporated.
Lastly mix in ¼ cup of pink jimmies, the long skinny sprinkles. Any other kind of sprinkle will completely melt away in the cake when baked.
Evenly divide the cake batter between 3 6" cake pans. Bake the cakes for 30-34 minutes, or until a cake tester/toothpick comes out clean from the centers. Let the cakes cool in the pans for 15 minutes, then transfer them to a cooling rack to completely cool.