• Prepare three 8" cake pans. Grease, flour and then line with parchment paper.
• Mix butter and sugar until light and fluffy.
• Add the three eggs and two egg whites, sour cream and vanilla.
• Add all dry ingredients to a bowl.
• Spoon in dry ingredients intermittently with buttermilk, ending with buttermilk.
• Scrape down the sides of the bowl to make sure all things are incorporated.
• Pour sprinkles into batter and mix by hand.
• Divide batter evenly into three cakes pans.
• Bake in a preheated 350° oven.
• Cook for 30 minutes or until cake springs back when touched.
• Place pans on a cooling rack for 10 minutes. Loosen cakes from pan with an offset spatula and turn upside down on rack.
• Peel off the parchment paper and cool completely.

Buttercream Frosting

• Beat butter until light and fluffy. Gradually add powdered sugar intermittently with heavy cream.
• After all powdered sugar, vanilla, salt and heavy cream are added, beat for 4 minutes, scraping down the bowl 2 or 3 times.
• Frost the cake with a thin layer of frosting for crumb coat.
• Add sprinkles to the rest of the frosting or follow instructions above in the blog post for decorative ring around the bottom of the cake.

Assembling Cake

• Place a little frosting on a cardboard round to anchor cake.
• Place first cake on round, flat side up.
• Frost the first layer, add the second layer.
• Frost the second layer then add the third layer, flat side up.
• Frost the top and sides of cake with a thin layer of frosting using a bench scraper.
• Place in the refrigerator for 15 minutes.
• Add the sprinkles to the rest of the frosting and frost the sides and top of the cake.