To make this cake, you will need the following:
1 x 16.5 oz. box cake mix
1/3 cup vegetable oil
1 cup water
2 x 16 oz. cans frosting
1 x 24 oz. box black-colored fondant
1/4 cup powdered sugar
Non-stick cooking spray
Red food coloring (optional)
Fondant roller (or regular rolling pin, but fondant roller is optimal)
Greaseless cake board (or rectangular serving tray)
Ruler or measuring tape
Preheat oven to 350. Line a 9x13 pan with parchment paper.
Combine cake mix, eggs, oil, and water in the bowl of a stand mixer. Mix on low for 30 seconds, then medium for 2 minutes, scraping down sides of bowl as necessary.
Pour batter into lined pan, and place in preheated oven. Bake according to directions on the back of the box.
Once cake is cooked and toothpick inserted in center comes out clean, remove cake to cooling rack and cool until room temparture, 45-60 minutes.
Take out your ruler/tape measure. Carefully measure and slice two 2.5 inch by 13 inch rectangles off of the cake, one from each side; set those aside. You will be left with a slim rectangle measuring 4 inches by 13 inches in the middle of your cake board.
Layer your tape measure/ruler at the base of the cake and measure 1.5 inches. Make two cuts roughly 1.25 inches in from the edge of the cake, on either side, and then cut up roughly 4 1/2 inches on an angle (again, on each side) to form what will be the leg portion of the body.
Use your knife to carve out indentations for the waist and the neck. Carefully use your knife to soften any sharp corners on the body. No flat, triangle heads here! Reserve all cake that is removed, as you will use it later.
The dimensions to the cake's body should roughly be as follows:
Length -- 13 inches
Head width -- 1 1/4 inches
Head length -- 1 3/4 inches
Shoulder width -- 4 inches
Feet width -- 1 1/2 inches
Leg length -- 4 1/2 inches
Remember, these are simply guidelines. If you can eyeball the cake and carve a body from it that way, feel free!
You don't want a flat body shape, because it won't look nearly as realistic. This is where the extra cake comes in! Cut and form leftover cake to add bulk to the face, chest, and foot area of your body. These are the areas that need dimension the most. It doesn't have to be pretty, it just has to add shape. We will glue it in place with frosting later, so don't worry if it looks messy!
Take out your frosting, and begin to frost the top and sides of the cake. There will be lots of crumbs, but that's totally okay! The fondant will cover all of this, and none will be the wiser.
Once your cake is totally covered in frosting, place the extra counter pieces over the "body". Use additional frosting to frost over these pieces, being careful not to tear them.
When the cake is completely frosted, use a paper towel to remove any additional frosting or cake crumbs from your cake board/tray.
Place cake, uncovered, in refrigerator for 2-3 hours, until totally chilled and frosting has formed a crust.
Remove fondant from package, and cut in half. Wrap other half of fondant and set side. Begin to knead the fondant until it becomes smooth and pliable, 2-3 minutes, adding additional powdered sugar as necessary.
Once fondant is softened, dust a bit more powdered sugar on your work surface and roll the fondant out. Roll into an oval shape that is roughly 8 inches wide and 19 inches long.
Carefully lift up fondant and rest on rolling pin. Transfer fondant over to cake and carefully drape fondant over the cake's surface.
Press fondant into bottom of cake, where the cake meets the board. Use a sharp knife to trim excess fondant from cake.
Pull 3, 1/2-inch balls of fondant from the excess and roll and shape them into 3, 6-inch long thin strips.
Using your fingers, carefully pinch folds into the indentations at the neck, waist, and ankles. This will help create the "bag" effect.
Brush a small amount of water on the neck, waist, and ankle area. Place fondant straps over the area brushed with water (water will adhere the straps to the cake). Trim any excess from the edge of the cake. Repeat until your 3 straps are in place and 'securing' the body in the body bag.
Use a pastry brush to carefully remove as much excess powdered sugar from the fondant as possible.
Use your pastry brush to brush oil over the sides of cake and in the crevices. This will remove any extra powdered sugar and give the fondant the shiny, plastic look the body bag needs.
To make the blood, open up a new can of frosting. Take out a tablespoon of frosting and mix in enough red food coloring to get a nice, deep red (it's blood, after all!).
Using a food-safe brush, brush the frosting "blood" on the body bag or cake board/tray as you see fit.
And that's it! Your body bag cake is ready to serve up and scare your friends and family!