Instructions

Bake the cake

1. Mix the flour, sugar, baking powder and salt in a large bowl.
2. Deb suggests that you add the pureed strawberries and then the butter to the dry ingredients, but I noticed in the comments that some people were having trouble with their hand mixers when mixing the puree with the flour (think motors blown out). Since I didn’t want to destroy my aunt’s hand mixer, I decided to mix the butter and strawberries first and then add them to the flour. The mixer had no problems with it, and it certainly didn’t affect the end result.
3. In a separate bowl (or the one you mixed your dry ingredients in, if you want to save the extra dishwashing), mix together the egg whites and milk. Add a drop or two of red food coloring, if you want your cake extra pink. Blend the eggs into the batter in two or three batches, mixing only to incorporate each time.
4. Butter your baking pans, or line them with parchment paper and butter the paper for extra credit. Divide the batter between the three pans evenly, and bake the cakes at 350F for about 30 minutes, until a toothpick inserted in the center comes out clean. Allow them to cool for 15-20 minutes before taking them out of the pan and cooling them completely on a wire rack.
5. To freeze the cakes (highly recommended, since it makes frosting much easier): once the cakes are completely cooled, trim off the tops so that the layers are completely flat. A long serrated knife works best. Then triple-wrap them tightly in plastic wrap and freeze. Deb also suggests flash-freezing as a layer cake technique: after putting the cakes on the wire rack, stick the rack in the freezer for 30 minutes, until the cakes are chilled, and then triple-wrap. I didn’t have enough freezer space for this though.
6. Make the frosting: cream the butter and cream cheese together until mixed well. Add the vanilla extract and then gradually mix in the powdered sugar.

Assemble the cake

1. Place one layer on the cake plate. Cover the top with an ample amount of frosting, about 1/3 of a cup. (I was concerned that I’d run out of frosting at the end, so I spread mine a little thin. Ultimately, I ended up with a ton of leftover frosting, so don’t be afraid to glob it on.) Top with the second layer, rinse and repeat.
2. Once your three layers are stacked, frost the top and the sides with what Deb calls a “crumb coat.” This is a preliminary layer of frosting designed to keep the cake in place and catch all those annoying crumbs. It makes for a much smoother frosting finish. Add a second layer of frosting, the “final frost” (yes, I made that up).
3. Decorate as you please: I mixed a drop of red food dye into a small amount of frosting and used a makeshift piping bag to create the polka dots. You could do sprinkles, something with strawberries, etc. etc.