Preheat Oven to 325F Degrees
FOR THE CAKE
1 box of white cake mix, sifted
1 c. cake flour, sifted
1 c. sugar
1 1/3 c. whole milk
1 c. sour cream
2 tbsp. vegetable oil
2 tsp. vanilla extract
4 egg whites
FOR THE FILLING
1 1/2 c. heavy whipping cream
2 cartons of strawberries (or 1 large carton)
FOR THE FROSTING
12 oz. of mascarpone cheese (1 1/2 containers)
2 tsp. vanilla
1 c. powdered sugar, sifted
2 c. heavy whipping cream
Optional: Graham Cracker Crumbs
For the Cake:
In the bowl of a stand mixer, fitted with paddle attachment, whisk together cake mix, flour and sugar. Then add in milk, sour cream, vegetable oil, and vanilla extract. Scrape down sides and mix again until well incorporated. Finally add in egg whites.
Grease 2-8 inch round pans. Divide batter equally among 2 pans. Bake for 30-40 minutes until the top of the cakes are slightly golden brown and inserted toothpick comes out clean. Allow the cake to slightly cool. Then turn them out and let cool completely.
If cake is not completely flat, use either a cake leveler or knife, to make cake completely even.
For the Filling:
In the bowl of a stand mixer fitted with whisk attachment, whip heavy whipping cream, on high speed until stiff peaks form. Set aside in refrigerator.
Using half a carton- hull strawberries and slice lengthwise. Set aside.
Then, place one carton of strawberries in the bowl of a food processor and pulse until the sauce appears to be like a "chunky applesauce." Using a strainer, push the strawberry puree through- to get rid of excess water. Fold strained strawberry puree (i.e., puree minus the water) into the whipped cream. The whipped topping will become a pink color when puree is well incorporated. Then fold in sliced strawberries.
Keep in refrigerator until assembling cake. Reserve 1/2 carton of strawberries for decorating.
For the Frosting:
In a medium bowl, whisk together mascarpone cheese, vanilla and powdered sugar with a spatula until well blended and smooth. Then, in the bowl of a stand mixer fitted with whisk attachment, whip heavy whipping cream, on high speed until stiff peaks form. Gently fold in whipped cream into the cheese mixture.
Assembling the Cake:
Place one 8-inch round cake on serving plate (on a cake turn table, preferred). Then using a large (1M) circle tip, pipe a border around the top (edge) of the cake (i.e., creating a wall). Make another border on top of the already piped border. You want a tall border to prevent the filling from spilling out. Within this border, place a large, heaping scoop of strawberry filling (you may not use all of the filling). Using a spatula, spread the strawberry filling over the top of the cake.
Gently place the second 8-inch round cake directly on top of filling, slightly pressing down and making sure the second layer of cake is perfectly aligned with the second. Cover cake with mascarpone frosting. Decorate as desired using the remaining frosting and strawberries.
Optional: After frosting the cake, but before decorating-- I chose to cover the side of the cake with graham cracker crumbs. I accomplished this by having a handful of graham cracker crumbs and pushing them against the side of the cake, very gently.