I saw on Pinterest a pumpkin shaped cake made using bundt pans. I used one box of Betty Crocker Devil's Food and one box of French Vanilla. Make sure to spray and flour the pan well so it doesn't stick. I made the frosting from scratch in two batches, one dyed green and one dyed orange. The stem is a ice cream cone sprayed with Wilton's Color Mist Spray. The jack o'lantern face is Wilton Sugar Sheet in black.
Buttercream Frosting
3 cups powdered sugar
2 sticks (1 cup) room temperature butter
2 tsp clear vanilla extract
2 tbsp heavy whipping cream
food coloring as needed.
I made one batch of green and then one batch of orange. I used the green to frost inside the round of the bundt, and to make the vines and the leaves.