Brittni Brown
October 18, 2018 1:12 pm

If you love Halloween, then you know that Halloween food is one of the greatest parts of the month. A classic Halloween party will feature spaghetti noodles (worms), peeled grapes (eyeballs) and, of course, peeled tomato (the heart). Halloween parties can be a sensory overload, so if you’re attending one this year, you’ll want to bring something that will capture everyone’s stomachs as well as their eyes.

This Halloween slime cake will literally ooze gooey green pudding when you cut into it, for a treat as messy as it is delicious. The chocolate is as decadent as Halloween itself; the slime is a creamy and mint flavored pudding. It looks terrifying, but it tastes like a Thin Mints cake. Serve immediately, and when you do, you won’t be able to look away from the spooky, scrumptious center.

Slime Cake

Serves 8 (serving size: 1 slice)
Active 1 hour, 30 min. Total 5 hours, 10 min.


Baking spray
2 (15.25-oz.) pkg. dark chocolate cake mix (such as Betty Crocker)
8 Tbsp., plus 1 tsp. black food coloring gel, divided
1 cup granulated sugar
6 Tbsp. cornstarch
1/4 tsp. kosher salt
4 cups, plus 5 Tbsp. whole milk
4 large egg yolks
1 tsp. neon green liquid food coloring
3/4 tsp. peppermint extract
1 cup (8 oz.), plus 2 Tbsp. unsalted butter, softened
2 (16-oz.) pkg. powdered sugar
1/2 cup Dutch-process cocoa blend (such as Hershey’s Special Dark)
2 Tbsp. activated coconut charcoal powder (optional)
1 tsp. vanilla extract


1. Preheat oven to 350°F. Coat three (8-inch round) cake pans with baking spray.

2. Prepare cake mix according to package directions, stirring 1 teaspoon of the black food coloring into batter. Spoon 2 cups of the batter into each prepared pan. (Discard remaining 2 cups batter or save for another use.) Bake in preheated oven until a wooden pick inserted in center comes out clean, 30 to 35 minutes. Cool in pans on a wire rack for 10 minutes; remove from pans. Cool completely on wire rack. Wrap cake layers individually in plastic wrap, and freeze for 1 hour.

3. Whisk together sugar, cornstarch, and salt in a medium saucepan. Slowly pour 4 cups of the milk into sugar mixture, whisking constantly, until blended and smooth. Whisk in egg yolks until blended. Cook milk mixture over low, whisking often, until thickened, about 15 minutes. Remove from heat, and stir in neon green food coloring, peppermint extract, and 2 tablespoons of the butter until butter is melted. Cover surface of pudding with plastic wrap, and refrigerate until chilled, about 1 hour. Before using, whisk pudding mixture to loosen.

4. Beat remaining 1 cup butter in a stand mixer fitted with a paddle attachment on high speed until creamy and fluffy, about 4 minutes. While beating at low speed, gradually add powdered sugar and cocoa blend, alternating with remaining 5 tablespoons milk, beginning and ending with powdered sugar, until smooth, about 3 minutes. Add charcoal powder, if using, along with vanilla and remaining 8 tablespoons black food coloring; beat on low until thoroughly blended, about 1 minute, stopping to scrape down sides as needed.

5. When ready to frost the cake, remove layers from freezer and unwrap. Cut a 2 3/4-inch circle from center of two cake layers. (You will have one cake layer that has no hole cut out).

6. Place a dollop of frosting in center of a cake stand or serving plate (to keep cake from sliding), and place one cake layer (the one with a hole) on top of frosting. Spoon 1 1/2 cups of the chocolate frosting into a zip-top plastic freezer bag. Snip 1 corner of bag, and pipe a ring of frosting around cake layer just inside top edge. Spoon about 2/3 cup of green pudding directly on top of first cake layer. Using an offset spatula, spread pudding evenly over top and just to edge. Repeat procedure with remaining one cake layer with a hole cut. Pour 1 cup of the green pudding into the vertical hole to fill all the way up. Place the third uncut cake layer on top.

7. Frost entire cake lightly with some of the frosting. Chill cake for 15 minutes. Spread remaining 3 cups frosting on top and sides of cake. Chill cake for 15 minutes.

8. Spoon about 1 cup of green pudding on top of cake; using an offset spatula, spread the pudding just to the edge. Spoon remaining pudding into a zip-top plastic freezer bag. Snip 1 corner of bag to make a small hole. Pipe vertical lines of pudding in varying lengths onto sides of cake. Serve immediately.