Preheat your oven to 350 degrees F. Prepare three 9-inch cake pans by lining the bottoms with parchment paper, then spraying the entire inside of the pans with nonstick cooking spray that includes flour. If you only have 2 pans, bake 2 cakes first, then bake the third cake immediately after.

In a big liquid measuring cup or a medium bowl, whisk together the milk, egg whites, and extracts. Set aside this mixture.

In the bowl of an electric mixer fitted with the whisk attachment, combine the cake flour, sugar, baking powder, and salt. Mix on low speed. With the mixer still running, add the butter a few pieces at a time. Increase the speed to medium and continue mixing until the mixture resembles moist crumbs, and the largest pieces are the size of small peas, about 3 minutes.

Pour in half of the milk mixture and mix on medium-high speed until the batter becomes light and fluffy, about 1 minute. Stop the mixer and scrape down the bowl. With the mixer on low speed, stream in the remaining milk mixture. Mix on medium-low for no longer than 30 seconds. If you notice the batter is a bit lumpy, don't worry about it! Just avoid over-mixing. Stop the mixer and gently stir the batter by hand a few times.

Next, evenly divide the batter among the three prepared cake pans. Bake at 350 degrees F for about 20-25 minutes or until a toothpick inserted into the center comes out with a few crumbs and no wet batter clinging to it. Let the cakes rest in the pans for about 5 minutes, then turn them out onto cooling racks to cool completely, about 1 ½ hours, before frosting. During this time, you can prepare the raspberry filling and frosting.

Add raspberries to a food processor and puree them.

Place a fine mesh sieve over a medium saucepan and pour the raspberry puree into it to discard the seeds. Press down on the puree with the back of a spoon or spatula until only the seeds remain. Make sure to wipe the back of your sieve to collect all of the puree.

Whisk cornstarch, sugar, and lemon juice into the puree until the cornstarch is mostly dissolved.

Bring the mixture to a simmer over medium-high heat, stirring constantly. Then, reduce the heat to medium (or medium-low if your stove runs hot) and continue to cook and stir continuously until the puree is thickened. It should be quite thick but still spreadable to prevent the cake layers from sliding around.

Refrigerate the filling until completely chilled. It will thicken further as it chills.

WHITE CHOCOLATE CREAM CHEESE FROSTING

Add chopped white chocolate and heavy cream to a microwave-safe bowl. Microwave for 30 seconds, then stir. Continue microwaving at 15-second intervals, stirring between each interval, until the chocolate is completely smooth. Set aside to cool for 5 minutes.

In a large bowl, beat cream cheese, butter, and salt at medium speed with a hand-held electric mixer until very creamy, about 1-2 minutes.

Beat in the melted white chocolate and vanilla extract until smooth.

Gradually add powdered sugar in batches, beating at low speed until blended after each addition. Refrigerate the frosting for about 30 minutes to help thicken it up. It should be on the thick side after chilling to stand up against the cake layers.

Spoon roughly 1 cup of frosting into a pastry bag (or a freezer bag with a small corner snipped off) to use for piping the dams of frosting. If you don't have a pastry bag, you can use a freezer bag with a small hole snipped in one corner.

Spoon ¾ cup of frosting into a small bowl to use for creating the crumb coat ("Crumb Coat Frosting"). Set it aside for later use.

Once the cakes are completely cooled, use a large serrated knife to level them so they're flat on top.

Prepare your serving platter or cake stand by lining the edges with four strips of parchment paper to create a square with a gap in the middle (this keeps the stand clean). Place a small dollop of frosting in the center to secure the cake, then place one cake layer on top, with the flat side facing up.

Pipe a ring of frosting just inside the top edge of the cake. Spread half of the chilled Raspberry Filling evenly to the edges of the piped frosting. Next, spread 1 cup of White Chocolate Frosting to cover the entire surface of the cake.

Add the second leveled cake layer on top, this time with the flat side facing down. Repeat the process of piping, filling, and frosting. Finally, place the third cake layer on top, again with the flat side facing down.

To create a crumb coat, spread a thin layer of the reserved Crumb Coat Frosting evenly over the cake, starting from the top and working down. Remove any extra frosting. Chill the cake in the fridge for 30 minutes until the crumb layer sets. While waiting, chill the remaining frosting and lightly beat it again before using.

Once the crumb coat is set, frost the outside of the cake with the remaining frosting as you like. Remove the parchment paper and pipe a ring of frosting around the bottom of the cake. Add raspberries for decoration if you'd like.