In a standing mixer, beat the butter until smooth and then beat in the sugar.

Little by little mix in the egg whites until combined.

In another bowl, sift the flour, baking powder, and baking soda together.

In a small dish, mix the yogurt with the milk and vanilla.

Add the yogurt mixture and the flour mixture -little by little into the butter mixture, alternating with the wet and dry ingredients. Scrape the sides to make sure it is well combined and you don't have any pockets of butter or dry ingredients.

Mix until smooth but try not to overmix.

Fold in the sprinkles and then transfer the batter onto your baking pan.

Place in the oven and bake for 25 to 30 minutes until the toothpick test comes out clean or the top springs back when pressed lightly in the center.

Remove from the oven and allow it to cool completely before decorating.

Once it is cool, spread the buttercream frosting on top in an even layer and add Funfetti sprinkles.

In a medium bowl, beat the butter with a mixer until it is light and creamy.

Add in the confectioner's sugar, whipping cream and the vanilla. Mix until combined.

Optional: You can fold in half of the funfetti/confetti sprinkles into the buttercream and add the rest sprinkled on top.