Preheat oven to 350F (175C) and prepare two 8” round cake pans by spraying with baking spray and lining the bottoms with parchment paper. Set aside.
Place quartered strawberries in blender and puree until smooth. Run through a fine mesh sieve over a measuring cup until you have 1 - 1 ¼ cups of juice. Do not discard berry pulp, set this along with any remaining pureed berries for the jam filling.
Pour strawberry juice into a small saucepan and cook over medium heat until reduced to ⅓ cup (pour into a measuring cup to check, if it’s not reduced enough, return to the saucepan and continue to cook until it is). This usually takes about 10 minutes.
Once reduced, add ⅔ cup milk to the strawberry reduction and whisk together. If using food coloring, whisk that in here as well. Set aside.
In a large bowl using an electric mixer or in a stand mixer, beat together oil, butter, sugar, and vanilla extract until completely combined.
In a separate bowl, whisk together flour, baking powder, and salt.
With mixer on low speed, gradually alternate adding the flour mixture and strawberry/milk mixture, stirring until just combined after each addition. (I start and end with the flour and add the flour mixture in 4 parts and the milk mixture in 3 parts.)
Place egg whites in a separate clean, dry bowl, and beat on high speed with an electric mixer until stiff peaks form.
Using a spatula, gently fold egg whites into cake batter until completely combined (don’t use your electric mixer at this point or you will over-beat the batter). Divide cake batter evenly into prepared pans and bake on 350F for 28 minutes or until toothpick inserted in the center comes out clean or with a few moist crumbs.
Allow cakes to cool in pans for 10 minutes then run a knife around the edges to loosen cakes from pan and invert onto cooling rack to cool completely. While cooling, prepare the jam filling.
Combine remaining strawberrry pulp, ⅓ cup sugar, cornstarch, lemon juice, and salt in a small saucepan and whisk to combine.
Cook over medium heat and bring to a boil. Boil, whisking constantly, until mixture is thickened and the whisk leaves a trail through the jam (this takes about 5-10 minutes).
Remove from heat, transfer to a heat-proof bowl, and place in the refrigerator to cool completely. Meanwhile, prepare your frosting.
WHIPPED CREAM CHEESE FROSTING
Combine cream cheese, ½ cup powdered sugar, vanilla extract, and salt in a large bowl and use an electric mixer to beat together until creamy and smooth.
In a separate bowl, combine remaining (1 cup, 125g) powdered sugar and heavy cream. Beat with an electric mixer until stiff peaks form.
With mixer on low speed, stir together the cream cheese and whipped cream until completely combined.
Once cake and jam are completely cooled place one layer of cake on serving tray. Use a piping bag fitted with a round tip (I use an Ateco 808) to pipe a dam around the layer. Fill with your jam filling.
Top with second layer of cake. Cover the entire cake with frosting.
Refrigerate until ready to serve. Enjoy!
Cake will keep refrigerated in an airtight container for up to 5 days.
¹May substitute 2 ⅔ cups (330g) all-purpose flour²Here are some recipes to use up your egg yolks!
For the red swirls in the decorative frosting on top of the cake, I just use a (food-safe) paintbrush to paint stripes of icing into the inside of my piping bag and then fill it with icing. You can see how I do this in my Pinata Cupcake recipe post.