For the Cake
1. Preheat your oven to 325 degrees F. Spray three 6-inch round cake pans with non-stick spray. Line the bottoms with parchment paper and spray again. Set aside.
2. In a medium bowl, combined the cake flour, baking powder, salt and all of the seasonings. Whisk to combine the ingredients evenly. Set aside.
3. In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and sugar on medium speed for about 3 minutes. Scrape down the sides and bottom of the bowl and mix again for another minute.
4. With the mixer on medium-low speed, add the eggs and egg yolks, one at a time. Make sure to mix well between each addition. Add the vanilla and stir to combine.
5. With the mixer on low speed, add 1/3 of the flour mixture to the sugar mixture. Stir for about 20 seconds and then add 1/2 of the buttermilk. Repeat the additions with another 1/3 of the flour mixture, the second half of the buttermilk and then the final 1/3 of the flour mixture. It's important to alternate adding these ingredients so they mix evenly, which will help your cake to rise more evenly. Only mix until the ingredients are incorporated. Over mixing your batter will cause it to be dense and/or sink in the oven.
6. Pour about 16 ounces of batter into each of the three 6-inch cake pans. Bake the cake layers on the middle rack in your oven for 35 to 40 minutes. Watch this cake closely at the end. Over baking your cakes will cause them to taste dry. When you insert a toothpick in the center of this cake, it should come out with a few moist crumbs on it.
7. Let the cakes cool in the pans for about 10 minutes, before inverting them onto cooling racks to cool completely. Once cooled completely, you can level the cakes and then wrap them in plastic wrap and freeze them until you're ready to stack and decorate the cake.
For the Buttercream
1. Heat your cream in a microwave safe bowl for about 1 minute. Pour the cream over the white chocolate chips and stir until all of the chips are melted. Set aside.
2. In the stand mixer fitted with the paddle attachment, beat the butter on medium-high speed for a couple minutes on its own. The butter will get lighter in color and texture.
3. With the mixer on low speed, gradually add the powdered sugar until combined. Add the vanilla and salt.
4. With the mixer on medium speed, slowly add the cream and white chocolate mixture. Once added, turn the mixer to medium-high speed and beat for about 3 minutes. The frosting should be silky smooth.
1. Place your first cake layer, top side up, on a cake board or cake plate. Cover the cake layer with about 3/4 cup buttercream and spread evenly, making sure to get eye level with the cake to ensure it's even.
2. Place your raspberries on the buttercream and press into place with your fingers.
3. Follow the above steps for the second cake layer, buttercream and raspberries.
4. Place the final cake layer, top side down, on the raspberries and buttercream. Apply a thin coat of frosting around the entire cake to lock in the crumbs. Freeze your cake for about 10 to 15 minutes to set the crumb coat and lock in your crumbs.
5. After the crumb coat is set, use the remaining frosting to decorate your cake. Garnish with the remaining fresh raspberries and serve the cake at room temperature.