Oreo Cookies and Cream Sheet Cake with Oreo Buttercream

Oreo Cookies and Cream Cake

Chopped Oreos run through the pale vanilla crumb of this scratch sheet cake, while finer cookie crumbs fleck the buttercream on top. Folding the larger pieces in at the end keeps them distinct instead of turning the batter gray.

Bake the cake in one 9×13-inch pan, then cut it into thick squares with the cookie-studded sides exposed. Add a whole Oreo to each serving just before serving so the garnish stays crisp.

Prep: 30 minutes | Bake: 32–35 minutes | Total: about 2 hours, including cooling | Serves: 12

Ingredients for Oreo Cookies and Cream Cake

For the cake

• 2½ cups all-purpose flour (300g)
• 1½ cups granulated sugar (300g)
• 2½ teaspoons baking powder
• ¾ teaspoon fine salt
• ¾ cup unsalted butter, softened (170g)
• 4 large egg whites, at room temperature
• ½ cup full-fat sour cream (120g)
• ¾ cup whole milk (180g)
• 2 teaspoons pure vanilla extract
• 12 regular Oreo cookies, roughly chopped

For the frosting and garnish

• 1 cup unsalted butter, softened (225g)
• 4 cups confectioners’ sugar (480g)
• 6 Oreo cookies, finely crushed
• 2–4 tablespoons heavy cream, as needed
• 1 teaspoon pure vanilla extract
• 12 whole Oreo cookies, one for each serving

Optional: 1–2 tablespoons extra finely crushed Oreo crumbs for sprinkling over the frosting.

How to Bake Oreo Cookies and Cream Cake

1. Prepare the pan and cookies. Preheat the oven to 350°F (175°C) with a rack in the center. Lightly grease a 9×13-inch baking pan; line the bottom with parchment if desired. Chop 12 Oreos into irregular ¼–½-inch pieces for the batter. Finely crush 6 more for the frosting and keep them separate.
2. Mix the vanilla batter. Whisk together the flour, baking powder, and salt. In a large bowl, beat the ¾ cup cake butter and granulated sugar until creamy. Beat in the egg whites, sour cream, and 2 teaspoons vanilla. Add the flour mixture in portions, alternating with the milk. Scrape the bowl as needed and stop mixing when no dry flour remains.
3. Fold in the cookies. Gently fold the chopped Oreos into the batter with a spatula, stopping as soon as they are distributed. Spread the batter into the prepared pan.
4. Bake. Bake uncovered on the center rack. Begin checking at 30 minutes; the cake will likely take 32–35 minutes. The top should be set and lightly golden, the center should spring back lightly, and a toothpick inserted in the center should come out clean or with a few dry crumbs. If it has wet batter on it, bake a few minutes longer and check again.
5. Cool completely. Set the pan on a cooling rack for about 1 hour or longer, until the center and pan no longer feel warm. Frosting a warm cake can melt the buttercream or pull at the crumb.
6. Make the buttercream. Beat the 1 cup frosting butter until smooth. Gradually beat in the confectioners’ sugar and 1 teaspoon vanilla; sift the sugar first if it is clumpy. Add heavy cream a tablespoon at a time until the frosting is spreadable, then mix in the fine Oreo crumbs. Add a little more cream if it is stiff, or a little more confectioners’ sugar if it is too loose.
7. Frost and serve. Spread the buttercream over the top only, making loose swirls and leaving the cake sides unfrosted. Sprinkle with extra crumbs, if using. Cut into 12 generous squares and place one whole Oreo on each shortly before serving.

How to Keep the Cookie Pieces Distinct

Use roughly chopped Oreos in the batter rather than fine crumbs, and fold them in by hand only after the vanilla batter is mixed. Excess mixing breaks down the cookies and can make the pale cake look gray. Save the finely crushed cookies for the buttercream, where they create small, even flecks.

When Is the Sheet Cake Done?

Treat 32–35 minutes as a guide, not an exact finish time. A dark or glass pan may bake and brown differently from a light-colored metal pan. Check the center for light spring-back and use a toothpick to confirm there is no wet batter; the top does not need to be deeply browned.

Storing and Freezing

Cover and refrigerate the frosted cake for 3–4 days for best quality. Keep the whole-cookie garnishes separate and add them just before serving. Let refrigerated portions sit briefly toward room temperature for softer cake and frosting.

The cake can be baked and cooled ahead, then covered until it is ready to frost. To freeze the frosted cake, wrap it well and freeze for up to 2 months without the whole-cookie garnishes. Thaw overnight in the refrigerator, bring toward room temperature, and add fresh Oreos before serving.

Nutrition

Approximate nutrition per serving, based on 1 of 12 squares including one whole Oreo: 770 calories, 7g protein, 37g fat, and 105g carbohydrates. Approximate nutrition per 100g: 420 calories, 4g protein, 20g fat, and 57g carbohydrates. Values vary with ingredient brands and portion size.