I made this for Nathan's birthday.
I found the recipe here
The recipe looks a lot more complicated than it actually is.
2 18.5 ounce boxes chocolate cake mix
8 large eggs
2 cups buttermilk
1 cup vegetable oil
1/4 cup green decorating sugar or granulated sugar
8 spearmint leaf gummy candies
1 yellow sugar sheet made by Wilton's
1 16-ounce tub vanilla frosting
1 16-ounce tub chocolate frosting
3/4 teaspoon yellow food coloring
5 drops red food coloring
2 tablespoons crispy rice cereal
*their recipe calls for orange fondant to make the cheese....but I used the sugar sheet to make it easier. Also, instead of using the food coloring, I used Wilton's brown food paste coloring (just a tiny bit, because honestly when you add the chocolate frosting to the vanilla it makes a nice light brown color anyway).
Preheat the oven to 350 degrees F. Spray a 2 1/2-quart ovenproof bowl and two 8-inch-round cake pans with cooking spray. Beat the cake mix, eggs, buttermilk and vegetable oil in a large bowl with a mixer.
Make the lettuce: Sprinkle some green or white sugar on a cutting board (I used wax paper). Roll out the spearmint candies to 1/8 inch thick with a rolling pin, sprinkling with more sugar to keep the candies from sticking.
Cut each flattened gummy piece into 3 strips. Fold each strip accordion-style to make ruffles; pinch the ends together.
Trim the top of 1 round cake and the flat side of the bowl cake to make them level; crumble the trimmings. Mix the vanilla frosting, 4 tablespoons chocolate frosting and the yellow and red food coloring in a bowl to make a light brown frosting.
Make the bottom bun: Put the trimmed round cake on a serving plate or cake board. Frost with some of the light brown frosting. Arrange the gummy-candy ruffles around the edge of the cake.
Make the patty: Spread the remaining chocolate frosting over the top and sides of the untrimmed round cake. Press the crumbled cake trimmings into the frosting.
(this is what the sugar sheet looks like, in case you were wondering)
Assemble the burger: Put the chocolate patty on the bottom bun, then drape the sugar sheet on top. Frost the bowl-shaped cake with the remaining light brown frosting; place on the patty. Press the rice cereal into the frosting.
This makes for one Very Happy Birthday boy!