Preheat your oven to 350F (175C) and prepare three 8-inch round cake pans by lining the bottom of each pan with a round of parchment paper and greasing the sides with baking spray.

In the bowl of a stand mixer (or in a large bowl using an electric mixer) whisk together flour, sugar, baking powder, and salt.

Turn mixer to low-speed and add butter, one tablespoon at a time, not adding the next until the first is completely combined.

Add canola oil and stir until combined, then add sour cream and vanilla extract, stirring on low-speed until completely combined. With mixer still on low-speed, add milk until combined.

In a separate clean, dry bowl, beat egg whites to stiff peaks.

Gently fold the whipped egg whites into the batter, ensuring no lumps remain. Carefully fold in broken Oreo pieces.

Divide batter evenly into prepared baking pans and bake for 30-35 minutes until a toothpick inserted comes out clean.

Allow cakes to cool in pans for 15 minutes, then invert onto a cooling rack to cool completely.

Cream together butter and cream cheese until creamy and well-combined.

Gradually add powdered sugar with mixer on low-speed, stirring in salt and vanilla extract.

Add cream, gradually increasing speed to high, and beat until light and smooth.

Evenly ice the cake with approximately ⅔ of the icing, pressing pulverized Oreo crumbs halfway up the sides.

Mix remaining Oreo crumbs into the frosting, then pipe swirls around the top of the cake.

Serve and enjoy.