Set your oven to preheat at 350°F and prepare two 9-inch round cake pans by greasing and lining them with parchment paper rounds.
In a large bowl, whisk together the sifted cake flour, baking powder, baking soda, and salt.
Using a stand mixer or hand mixer, cream the butter on medium-high speed for about a minute until smooth and creamy.
Slowly add the granulated sugar and continue beating at high speed for 2 minutes until fluffy.
Reduce mixer speed to low and gradually add the egg whites in increments, beating well after each addition and scraping the bowl as needed.
Combine vanilla extract, almond extract, milk, and sour cream in a measuring cup and mix well.
Alternate adding the flour mixture and the milk mixture to the butter mixture in three additions, beginning and ending with the flour, mixing on low speed until just combined.
Divide the batter evenly into the prepared pans and smooth the tops.
Bake the cakes for 25 to 30 minutes until edges are lightly browned and a toothpick inserted in the center comes out clean.
Allow cakes to cool in their pans set on a wire rack for 15 minutes, then invert onto racks to cool completely.
For the frosting, beat the butter at medium speed until completely smooth.
Slowly add sifted confectioners’ sugar on low speed, mixing until fully combined.
Blend in salt, heavy cream, amaretto, and almond extract, mixing until smooth.
Fold in melted white chocolate and beat at medium-high speed for one minute until creamy.
Slice each cooled cake horizontally into two equal layers to create four layers in total.
Place one cake layer on a serving platter and spread 1/2 cup of the buttercream evenly over it, then layer 1/4 cup of raspberry preserves on top.
Repeat with the next two layers, finishing with the top cake layer.
Cover the entire cake with the remaining frosting on top and sides.
Press sliced almonds gently around the sides of the cake and decorate the top with fresh raspberries.
Let the cake rest for 20 minutes before cutting to allow it to set.
Serve immediately or refrigerate for up to two days; bring to room temperature before enjoying.
