It's The Great Bundt-kin, Charlie Brown

Directions

1. Preheat the oven to 350°F and thoroughly grease a 12-cup Bundt pan with cooking spray. In a large bowl, use an electric mixer on low speed (or a stand mixer with the whisk attachment) to beat together 1 box cake mix, 1 box pudding mix, 4 eggs, 1 cup pumpkin puree, 1/3 cup vegetable oil, 1/4 cup sour cream, 1 1/2 teaspoons pumpkin pie spice, 1 teaspoon vanilla extract, and 1/2 cup water until combined. Scrape down the bowl and beat again to incorporate.
2. Pour the batter into the prepared pan and smooth the top with a rubber spatula.
3. Bake for 40 to 50 minutes, until a tester inserted into the center comes out clean. Let the cake cool in the pan for 15 minutes, then invert it onto a wire rack to cool completely.
4. Clean the pan. Repeat the process with the remaining 1 box cake mix, 1 box pudding mix, 4 eggs, 1 cup pumpkin puree, 1/3 cup oil, 1/4 cup sour cream, 1 1/2 teaspoons pumpkin pie spice, 1 teaspoon vanilla extract, and 1/2 cup water.
5. Place 1 3/4 cups frosting into a heatproof 2-cup measuring cup. Add orange food coloring and stir until you reach the desired shade.
6. Using a large serrated knife, level the rounded bottoms of both cooled cakes. Arrange one cake on a platter with the smooth side up, then spread 3/4 cup of the orange frosting on top. Place the second cake on top, adjusting so the edges align. If using dowels, insert them and trim as needed. Refrigerate for 15 minutes.
7. Meanwhile, in a small bowl, mix 3 tablespoons of frosting with green food coloring until you achieve the desired shade. Spread the green frosting over the ice cream cone. Decorate with green sprinkles if desired.
8. Microwave the remaining orange frosting in 3-second increments, stirring between each, until just pourable (about 10 seconds total). Slowly pour the orange frosting over the cake in a circular motion to create a drip effect. Decorate with orange sprinkles if desired.
9. Fill the holes of the cake with Halloween candy if using. Place the frosted ice cream cone upside down on top of the cake.