Preheat the oven to 350°F/177°C and prepare three 6-inch or two 8-inch cake pans by spraying the sides with baking spray and fitting a parchment paper circle to the bottom of each pan.

In a medium bowl, add the flour, baking powder, baking soda and salt. Whisk together and set aside.

In the bowl of a stand mixer fitted with the paddle attachment, beat the butter at high speed until creamy, about 2 minutes. Add the sugar and cream it together with the butter at medium-high speed until light and fluffy, about 2 minutes, scraping the bowl and paddle at the halfway point.

Turn the mixer to low and add the egg whites one at a time, mixing until they are just combined and scraping down the bowl and paddle as needed. Add the vegetable oil and vanilla, increase the mixer speed to high and beat for 1 minute.

Turn the mixer off and add the flour mixture all at once. Mix the ingredients on low speed until just combined, then slowly pour in the buttermilk. Continue mixing at low speed for about 30 seconds, until the batter is uniform and combined.

Divide the batter evenly between the prepared cake pans and bake for 28 to 32 minutes. Let the cakes cool in their pans for 5 minutes, then remove them from the pans and allow them to cool completely on a wire rack.

Preheat the oven to 250°F/121ºC and line a baking sheet with parchment paper.

In a medium bowl, whisk together the cake flour, sugar, baking powder, and salt.

Add the melted butter and vanilla extract. Mix with a rubber spatula until the mixture begins to form small clusters.

Spread the clusters onto the prepared baking sheet and bake for 30 minutes. Cooling the crumbs completely before using in the cake assembly.

In a medium bowl, mix together the sliced strawberries, strawberry jam, and granulated sugar. Let sit at room temperature or in the refrigerator.

Chill the metal bowl of your stand mixer for 15-20 minutes in the refrigerator or freezer.

Sprinkle the gelatin into a small glass measuring cup or microwave safe dish. Add the cold water and whisk until the gelatin is dissolved.

Add the heavy whipping cream, powdered sugar, and vanilla extract into the chilled metal bowl of your stand mixer fitted with the paddle attachment and mix on low speed to combine. Turn the mixer to high speed and beat until thickened.

With the mixer on low speed, drizzle the liquid gelatin into the cream. Slowly increase the speed to medium-high and continue to beat until you have reached stiff, fluffy peaks.

Once the White Cake layers are cooled, level them to your desired height. Add the first layer onto a cardboard cake round on your turntable or cake stand.

Add some of the strawberry juice onto the cake layer as a soak.

Fit a piping bag with a Wilton Tip 6B and fill it with the Whipped Cream Frosting before piping shells along the outer edge of the cake layer.

Pipe a second row of shells to fill in the center of the cake layer. Top with about ⅓ Cup of the strawberries and sprinkle a handful of shortbread crumbs on top.

Place the next cake layer on top and repeat the process of adding the strawberry juice soak, piping the Whipped Cream Frosting shells, topping with strawberries, and sprinkling shortbread crumbs.