Ingredients

Chocolate Cake:

• 3 cups (415g) all purpose flour
• 2 & 1/2 cups (530g) white granulated sugar
• 1 cup (95g) unsweetened natural cocoa powder (not Dutch process)
• 1 tbsp baking soda
• 1 & 1/2 tsp baking powder
• 3/4 tsp kosher salt
• 3/4 cup (177ml) vegetable oil
• 3 eggs, room temperature
• 2 tsp vanilla extract
• 1 & 1/2 cups (335ml) full-fat buttermilk*, room temperature DIY recipe in the notes
• 1 & 1/2 cups hot water

Oreo Buttercream:

• 2 cups (452g) unsalted butter, room temperature
• 6 cups (720g) powdered sugar
• 4 tsp vanilla extract
• 4 tbsp whole milk, room temperature
• 1/4 tsp kosher salt
• 18 Oreo cookies, filling removed

Instructions

Make The Cake:

Preheat the oven to 350°F and prepare three 8-inch cake pans by spraying the sides with cooking spray and fitting the bottoms with a wax paper or parchment cake circle.  Place all of the dry ingredients into the bowl of a stand mixer and stir on low for 30 seconds to fully combine them. Add the vegetable oil, eggs, vanilla, and buttermilk and mix on low until just combined. With the mixer still on low, add the hot water in a slow stream, then turn the mixer to medium and beat until smooth, about 2 minutes. The batter will be very thin.  Pour into prepared cake pans no more than 2/3 full and bake for 40-45 minutes, until a wooden toothpick inserted comes out clean. (Note that this recipe makes more batter than you’ll need.  I made cupcakes with the additional batter.)  Cool completely.

Make The Oreo Buttercream:

After removing and discarding the filling from the Oreo cookies, use a food processor to blend them into a fine crumb. Set aside. In the bowl of a stand mixer, cream the butter on med-high until light and fluffy (about 5 minutes), scraping down bowl and paddle a few times in between. Add powdered sugar a few cups at a time, scraping down bowl and paddle between intervals. Mix on medium until fully incorporated.  Turn mixer to low and add vanilla, milk, and salt. Mix on medium for one minute. Scrape down bowl and paddle and add the Oreo cookie crumbs. Mix for another minute on medium until incorporated.

Assembly:

Fill and frost the Chocolate Cake layers with Oreo buttercream. If you want to recreate the same look as pictured, chill the frosted cake for 20 minutes before adding a  chocolate ganache drip.  Check out this link…it takes you right to the Sugar and Sparrow website where she’s done a wonderful job of explaining ganache. 

I used Wilton tips 1M and 4B to pipe rosettes and open stars as a border around the top edge, then added Mini Oreos and these sprinkles.

Chef’s Notes:

DIY Buttermilk recipe: add 1 tbsp of white vinegar for every cup of whole milk you’ll be using. For this recipe, add 1 1/2 tbsp of white vinegar to a jar and top it with 1 1/2 cups of whole milk. Stir and let sit for 15 minutes before using in the recipe. 

Make ahead tips: the Chocolate Cake can be made ahead and stored at room temperature, covered tightly in plastic wrap, for up to two days. Alternatively, you can cover with plastic wrap and store in the freezer for up to two months before thawing to room temperature.

The Oreo Buttercream can be made ahead and stored at room temperature in an airtight container for up to one day. Alternatively, you can store it in an airtight container in the refrigerator for up to two weeks. When you’re ready to use it, bring it back to room temperature and re-whip with your stand mixer to bring it back to frosting consistency.

Recipe from Sugar and Sparrow