Prep time: 20 min.Baking time: 50-60 min.Decoration time: 25 min.
Preheat oven to 350 degrees. Line the pan with wax paper, grease and flour. Reserve 16 SNICKERS® Brand Mixed Miniatures. Unwrap the rest and roughly chop them. Set aside.
Prepare cake mix according to the package instructions. Fold the chopped SNICKERS® Brand Mixed Miniatures into the batter before pouring it into the prepared pan, and bake for 50-60 minutes, until an inserted toothpick comes out clean. Unmold the cake and transfer to a wire rack to cool completely.
Reserve 1 tablespoon of chocolate frosting and put into a re-sealable bag with a corner snipped. Set aside.
Tint remaining vanilla frosting yellow. Set aside.
Cut off the top third of the cake lengthwise. Place the bottom piece on a serving platter. Frost the sides of the cake with chocolate frosting, and the top with yellow tinted vanilla frosting. Spoon a tablespoon of yellow frosting into a re-sealable bag with a snipped corner and pipe a decorative edge around the top edge of the cake.
Place the cake on a serving plate with the front of the cake towards you. Arrange the unwrapped candies around the front area of the yellow tinted frosting. Let the candies spill over the edge.
Place the top cake at an angle, so that the "chest" looks slightly open. Carefully frost the top piece with the remaining chocolate frosting. Pull the tines of a fork through the chocolate frosting, creating a wood grain effect on the cake.
Using the photo as your guide, decorate the chest as follows:
Line M&M'S® Brand Milk Chocolate Candies on the top and sides of the chest to look like decorative bands.
Press an unwrapped TWIX® Brand Miniature on each side of the chest as handles, and place a yellow M&M'S® Brand Milk Chocolate Candies piece on both sides of each handle.
Slightly flatten a yellow STARBURST® Brand Tropical Fruit Chew piece as a lock. Use the reserved chocolate frosting to pipe a keyhole at the center of the STARBURST® Brand Tropical Fruit Chew, and attach at the center of the lid.
Sprinkle ground vanilla wafers around the chest as "sand". Scatter M&M'S® Brand Milk Chocolate Candies, TWIX® Brand Miniatures, SNICKERS® Brand Mixed Miniatures, M&M'S® Brand Peanut Chocolate Candies and STARBURST® Brand Tropical Fruit Chews over the "sand" for treasures.