Preheat the oven to 350°F and line 3 6-inch round cake pans with parchment paper. Set aside.

Add flour, cornstarch, sugar, baking powder, and salt to the bowl of a hand mixer or stand mixer with the paddle attachment. Mix on low until combined.

Add softened butter and beat on low speed for 3-5 minutes until it looks like wet sand.

In a separate bowl, whisk the oil, vanilla, almond extract, sour cream, and milk together. Slowly pour it into the dry ingredients, mixing on low until a thick batter forms.

Mix in the eggs on low speed one at a time until the batter is smooth.

Scoop the cake batter evenly into the prepared pans. Bake for 20-30 minutes until a toothpick inserted in the center comes out with a few moist crumbs attached.

Let the cakes cool in their hot pans for 10 minutes, then transfer them to a wire rack to cool completely.

For the frosting, beat the butter, vanilla, almond extract, and salt on medium-high speed until smooth and creamy.

Add powdered sugar 1 cup at a time on low speed. Then mix in the almond extract on medium-low. Add heavy cream 1 teaspoon at a time until the desired consistency is reached.

To assemble, first remove the domes from the cakes with a serrated knife.

Pipe a dollop of buttercream on your cake stand or turntable, then place one cake layer on top. This will help keep the cake from slipping.

Pipe a tall ring of frosting around the edges (this is a cake dam that will keep the filling inside) and fill the center with the raspberry jam.

Lay the second layer on top and repeat the process with the almond filling.

Place the last layer on top upside down so the top is flat. Apply a thin, smooth coat of frosting, or crumb coat, all over the cake using an offset spatula, smoothing it out with a bench scraper. Chill the cake in the freezer for 20 minutes or until the frosting is dry to the touch.

Spread a thick final layer of frosting all over the cake. Garnish the cake with fresh raspberries and enjoy!