Preheat oven to 350F. Butter and line the bottoms with parchment paper of three 8-9" cake pans.

In a mixing bowl, whisk the flour, baking powder, and salt together. Set aside.

In a separate mixing bowl, beat the sugar, oil, eggs, egg whites, and vanilla together for 2 minutes.

Add the sour cream and buttermilk. Beat well.

Add the flour mixture and mix just until combined.

Evenly distribute the batter between the prepared cake pans.

Bake for 18-22 minutes, or when a toothpick inserted into the center comes out clean.

Let cool in the cake pans for 10 minutes, then transfer to a baking rack to cool completely.

Mix the chopped strawberries and sugar together. Let sit for 20-30 minutes while the cake bakes to get juicy.

In the bowl of a stand mixer fitted with the paddle attachment, combine the powdered sugar and softened cream cheese. Beat on medium speed until smooth, about 2-3 minutes.

Switch the paddle attachment with the whisk attachment. On medium speed, gradually pour in the heavy whipping cream. Beat until soft and fluffy peaks. Fold in the vanilla extract with a spatula.

Slice the very tops off the cooled cake layers so you have an even cake to layer.

Layer each cake layer with one third of the frosting and one third of the strawberries to enjoy!

Store at room temperature the day of, then in a cake container in the fridge up to 3-4 days.