Preheat the oven to 350 degrees F. Prepare three 8-inch round cake pans or four 6-inch pans with non-stick spray, parchment paper rounds, and another coat of non-sick spray. Set aside.

In a medium size bowl, sift the cake flour and baking powder. Set aside.

In the bowl of a stand mixer, fitted with the paddle attachment, beat the butter, canola oil, salt and sugar on high until fluffy and smooth, about 5 minutes. Add two drops of the pink food gel and vanilla. Mix well.

Add the egg whites, one at a time to the bowl and beat on medium until well incorporated.

Turn the mixer on low and add 1/3 of the flour mixture to the butter mixture until fully incorporated. Then add half of the sour cream and blend well, followed by another 1/3 of the flour, the second half of the sour cream and the final 1/3 of flour. Mix until incorporated.

Scrape down the sides of the bowl and mix on low for another 10 to 20 seconds.

Pour the cake batter evenly between the three pans (about 16 to 17 ounces of batter in each 8-inch pan or 12 ounces in each 6-inch) and bake about 23-25 minutes or until a toothpick inserted into the middle of the cake comes out clean or with just a few crumbs. Make sure not to over bake.

Remove cake from the oven and let cool in the pans for 10 minutes before inverting onto cooling racks.

In a stand mixer fitted with a paddle attachment, cream the butter on medium-high speed for about two minutes.

With the mixer on low speed, slowly add the sifted powdered sugar until incorporated. Scrape down the sides of the bowl and continue to mix for another minute.

Add the heavy cream, one tablespoon at a time. Once the cream is incorporated, add the raspberry emulsion and increase the speed to medium-high and beat the frosting for five minutes. It should get lighter in texture and color.

Add food coloring, if desired.

Before frosting your cake, make sure to mix the frosting by hand with a wooden spoon to push out the air pockets. 

Level each of the cake layers, if needed. Spread a small amount of frosting on a cake board to help hold the cake in place.

Place the first cake layer, bottom-side down, in the center of the cake board. Using an offset palette knife, spread about 2/3 cup frosting evenly across the cake layer. If using fresh raspberries, press about 1/2 cup raspberries into the frosting. 

Place the second cake layer on top of the raspberries and repeat step 2.

Place the final cake layer, bottom-side up, on top of the second layer and give the cake an even crumb coat, making sure to fill in uneven areas of the cake to create an even foundation for your main frosting.

Freeze the cake for 10 minutes to set the crumb coat.

Continue to frost the cake after the crumb coat is set.