Prepare one recipe of homemade raspberry sauce, then set aside to cool completely.

Position oven rack to the middle. Preheat oven to 350° F (177°C). Grease the bottom and sides of a 9x13 inch cake pan with nonstick spray. Set aside.

In a large bowl, sift the flour, baking powder, and salt and whisk to combine. Set aside.

In the bowl of a stand mixer fitted with the paddle attachment, or in a large bowl using a hand mixer, beat the butter on medium speed until creamy, about 1 minute.

While the mixer is running, slowly pour in the sugar and continue to beat until light and fluffy, about 4-5 minutes. Add sour cream and continue to mix until combined.

Scrape down the sides and bottom of the bowl. Lower the speed to medium-low and mix in the egg whites, one at a time until completely combined.

Add the oil, vanilla, and almond extract to the milk or buttermilk and set aside.

Add ⅓ of the dry ingredients and beat just until combined, then add ½ of the liquid mixture and mix until just combined. Continue mixing in ½ of the remaining dry ingredients, remaining liquids, then remaining dry ingredients. Remember to mix after each addition before adding the next.

Scrape down the sides and bottom of the bowl again to make sure everything is mixed in properly.

Pour the batter into the prepared pan and spread into an even layer. Bake for 30-35 minutes or until a toothpick inserted into the center comes out clean.

Remove the cake from oven and allow to cool completely on a wire rack.

Add white chocolate chips and heavy cream to a heat-safe bowl and microwave in 30 second intervals, stirring after each until completely melted, smooth, and combined.

Add a squirt of the icing whitener and stir until the ganache is completely white. Set aside to cool while you prepare the mousse.

Put the chopped white chocolate and ¼ cup of heavy cream into a small bowl. Microwave in 30 second intervals, stirring after each until fully melted and smooth. Set aside to cool completely.

In a medium stainless steel bowl, using a handheld mixer, whip the remaining 1 and ½ cups of heavy cream until it reaches soft peaks.

Add the 4 tablespoons of powdered sugar and vanilla extract and beat until cream reaches stiff peaks.

Pour in the cooled white chocolate ganache and gently fold until completely combined. Set aside.

Using a large straw or a skinny rod, poke rows of holes into the top of the cake.

Spoon raspberry sauce into one row and spoon ganache into the other row. Alternate between raspberry sauce and ganache.

Spread white chocolate mousse on top. Drizzle on the extra white chocolate ganache and raspberry sauce. Use a toothpick to swirl the drizzles with the mousse.

Top with fresh raspberries and white chocolate curls. To make the white chocolate curls, shave a room temperature white chocolate bar with a vegetable peeler. Refrigerate overnight if desired. Serve chilled or at room temperature.