• Preheat your oven to 350F (175C) and prepare three 8-inch round cake pans (see note 5 to make in two 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.
  2 ½ cups (315 g) all-purpose flour¹, 2 cups (400 g) granulated sugar, 1 Tablespoon baking powder, 1 teaspoon salt
• Turn mixer to low-speed and add butter, one tablespoon at a time, not adding the next tablespoon until the first is completely combined. When you’re finished, the mixture should resemble coarse sandy crumbs (see video above for visual).
  6 Tablespoons (85 g) unsalted butter softened to room temperature
• Add canola oil and stir until combined, then add sour cream and vanilla extract and stir on low-speed until completely combined. With mixer still on low-speed, add milk until combined.
  ⅔ cup (157 ml) avocado oil, canola oil or vegetable oil, ½ cup (120 g) sour cream, 1 Tablespoon clear vanilla², ¾ cup (175 ml) whole milk room temperature preferred
• In a separate bowl that is completely clean, dry, and grease-free, use clean, dry beaters to beat egg whites to stiff peaks (I show a visual of this in the post above and in the video if it's your first time doing this!).
  6 large or extra large egg whites³,
• Use a spatula to gently fold your whipped egg whites into batter (don’t overmix, but make sure there are no lumps of egg white remaining).
• Carefully fold in broken Oreo pieces. Divide batter evenly into prepared baking pans and transfer to 350F (175C) oven and bake for 30-35 minutes or until the tops spring back if lightly touched and a toothpick inserted in the center comes out clean or with a few moist crumbs. If your oven does not bake evenly you may need to rotate pans halfway through baking.
  20 Oreo cookies
• Allow cakes to cool in pan for 15 minutes then carefully invert onto cooling rack and allow to completely cool before assembling and decorating.

Cream Cheese Frosting (makes enough to decorate cake as seen in photos)

• Prepare frosting by creaming together butter and cream cheese with an electric mixer or stand mixer until creamy and well-combined.
  ¾ cup (170 g) unsalted butter, 12 oz cream cheese
• Gradually add powdered sugar with mixer on low-speed (or see my video for a tip for adding all the sugar at once without making a mess!), scrape the sides and bottom of the bowl, and stir in salt and vanilla extract. With mixer on low speed, add cream and gradually increase mixer speed to high. Beat for 15-30 seconds until light and smooth.
  5 ¼ cup (655 g) powdered sugar, ¼ teaspoon salt, 1 ½ teaspoons clear vanilla extract, 1 Tablespoon heavy cream
• Evenly ice cake (you'll only need approximately ⅔ of the icing for this), and once whole cake is covered in icing use your hands to press pulverized Oreo crumbs evenly halfway up the cake. Pour about 3-4 Tablespoons of remaining Oreo cookie crumbs into remaining frosting and stir to combine (you can adjust how many crumbs you'd like to use according to how light or dark you would like your frosting to be). Fit a large piping bag with Ateco 848 piping tip and fill with frosting. Pipe swirls around the top of the cake. Serve and enjoy.
  10 Oreo cookies