Makes: 12 servings
2 boxes spice cake mix
2 cans (15 ounces each) unsweetened pumpkin puree
2 cups honey Greek yogurt
6 cups powdered sugar, sifted
1 pound unsalted butter, at room temperature
1 teaspoon pumpkin pie spice
1⁄4 to 1⁄2 cup heavy cream
2 tablespoons spiced rum
For cake: Preheat oven to 350°F. Coat two 8-inch round cake pans (2 inches deep) with cooking spray.
In a large bowl, with an electric mixer, combine 1 box cake mix, 1 can pumpkin, 1 cup yogurt, and 3 eggs and beat on low speed until batter begins to come together. Increase speed to high and beat for another 2 minutes. Divide batter between cake pans. Bake for 20 to 25 minutes, or until a wooden pick inserted in center comes out mostly clean. When pans are cool enough to handle, unmold cakes and cool on wire rack. Repeat with remaining ingredients to make two more layers.
For frosting: In a large bowl, with an electric mixer, combine sugar, butter, spice, and 1⁄4 cup cream and beat on medium until creamy. Add rum and beat until mixed. If frosting is too stiff, add cream, 1 tablespoon at a time.
To assemble, cool cakes completely. Place one layer onto pedestal, and frost with about 1⁄2 cup of frosting. Repeat twice. Place final layer on top and frost tops and sides.