10Oreo cookiespulverized to fine crumbs (if any significant pieces remain they will clog your piping tip)
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.
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).
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.
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!).
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.
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.
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.
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.
¹ Cake flour: You may substitute 2 ¾ cup or 315g cake flour, if desired² Clear vanilla extract helps to keep the cake bright white (rather than tinted slightly yellow) but regular extract can be used instead.³Egg whites: I recommend fresh and not carton egg whites. Some readers have used carton egg whites with success, but for others they never whip to stiff peaks (and many say on the side of the packaging that they will not), so whether or not they will work for you is a bit of a gamble.⁴ Here are a few of my other favorite frosting options:Swiss Meringue Buttercream Chocolate Cream Cheese Frosting Ermine Frosting⁵Baking in two pans instead of three: This recipe can be made in two 8” or 9” round pans but only fill each pan ⅔-¾ of the way full and discard any extra batter, otherwise it will overflow in your oven. Two 8” pans will take approximately 35-40 minutes, and two 9” pans will take a bit less time. Keep in mind dark-colored pans typically take less time in the oven and light-colored pans usually require longer.
This cake will keep in an airtight container at room temperature for 1-2 days or refrigerated for up to a week (unfortunate fact: refrigerators dry out cakes!). It may also be frozen for several months. Please see the post for more detailed information about storing.