For the White Almond Cake:
Preheat your oven to 350°F (177°C). Prepare three 7-inch round cake pans with nonstick cooking spray and parchment paper circles.
In a mixing bowl, whisk together the cake flour, baking powder, and salt. Set aside.
In a stand mixer with a paddle attachment, cream together the sugar, butter, and vegetable oil until pale and creamy.
On low speed, add the egg whites one at a time, mixing in between each addition. Then, add the sour cream, vanilla extract, and almond extract. Mix on medium speed until combined.
Alternate adding the flour mixture and milk to the butter mixture, beginning and ending with the flour (⅓ flour, ½ milk, ⅓ flour, ½ milk, ⅓ flour). Mix until smooth, but don’t overmix.
Divide the batter evenly into the prepared pans. Bake for 26-30 minutes, until the cakes bounce back when touched or a toothpick comes out clean. Let the cakes cool in the pans for 15 minutes, then transfer to a wire rack to cool completely.
For the Shortcut Swiss Meringue Buttercream:
In a stand mixer fitted with a whisk attachment, whip the egg whites, powdered sugar, and salt for about 5 minutes until thick and opaque.
On low speed, add the cubed butter one piece at a time, mixing until incorporated. Add the vanilla and almond extracts.
Whip the buttercream on high speed for 10-20 minutes until smooth and creamy. If the frosting curdles or separates, continue whipping until it becomes silky. Switch to a paddle attachment and mix on low to remove air bubbles.
For the Raspberry Filling:
In a medium saucepan, cook the raspberries, sugar, and lemon juice over medium heat for 10 minutes until bubbling.
Mix the cornstarch and water in a small bowl, then stir it into the raspberry mixture. Remove from heat and strain the mixture through a fine mesh strainer to remove seeds. Let the filling cool to room temperature, then chill for at least 1 hour.
Assembling the Raspberry Almond Cake:
Level the cooled cake layers with a serrated knife. Place one cake layer on a cake board, spread a thin layer of buttercream on top, and pipe a border around the edge. Fill the center with half the raspberry filling. Repeat with the second cake layer.
Add the final cake layer, crumb coat the entire cake with buttercream, and chill for 20 minutes. Frost the cake with a generous layer of buttercream and smooth the sides.
Decorate with fresh raspberries and slivered almonds. Enjoy!