Celebration Cake with Raspberry Buttercream

Directions

1. Grease two 9 inch cake pans and line the bottoms with parchment paper. Preheat oven to 350F
2. In a bowl of a stand mixer fitted with a paddle attachment beat the butter and sugar at medium speed until it's light and fluffy about 5 minutes. Occasionally stop the machine to scrape down the sides of the bowl.
3. Add the extracts and beat until combined.
4. Add the sour cream to the milk and mix the two together. In a medium bowl sift together the flour, salt, and baking powder. Set aside.
5. Gradually add the flour mixture to the butter mixture alternating between the flour and the milk mixture. Start and end with the flour mixture. Transfer the batter to a large bowl and set it aside.
6. Clean the bowl of the stand mixer and use the whisk attachment to beat the egg whites on high speed until stiff peaks form. With a rubber spatula take half of the egg whites and fold them into the batter. Fold in the remaining half. Gently fold the sprinkles into the batter.
7. Divide the batter evenly between the two pans and bake for 23-30 minutes. Cakes are done when a toothpick inserted into the middle comes out clean. Set to cool on a cooling rack.
8. Let cakes cool for 15 minutes then turn out onto a cooling rack and let cool completely.
9. For the raspberry puree- Place the raspberries, 70 grams of sugar, 1 teaspoon vanilla, and a pinch of salt in a saucepan. Cook over medium heat until the berries start to release their juices. Turn off the heat and set aside to cool. Once cool place the raspberry mixture into a blender and puree. Pass the mixture through a sifter to catch all the seeds. Use the back of a spoon to push on the seeds to get as much raspberry juice as you can to go through the sifter. Discard the seeds.
10. For the buttercream- In the bowl of a stand mixer add the 240 grams of sugar, egg whites, salt, and cream of tarter. Place the bowl on top of a saucepan of simmering water. Whisk the mixture until the sugar has dissolved. You can test it by rubbing some of the mixture between your thumb and index finger if it feels smooth then it's done. If it feels grainy then it needs more time.
11. Remove the bowl from the heat and beat using the whisk attachment on high speed for about 5-10 minutes until the meringue is at room temperature.
12. Once at room temperature continue whisking as you add the butter one tablespoon at a time. Once all the butter has been added add 1 teaspoon vanilla as well as 180 grams of the raspberry puree. Beat until it's mixed in. The buttercream should be silky smooth. If it appears soupy then the meringue was too warm when the butter was added. Place the bowl in the fridge for 10-15 minutes then re-whip it.
13. Decorate the cake as desired. You may have a little frosting leftover which can be used for flowers or other decorations.