Prepare cake according to package directions and bake as directed. Let cool completely. Crumble cake into a large mixing bowl. I like to cut the cake into pieces and use my fingers to crumble it. Add ¾ tub of frosting and mix well (using your fingers works best).
Place wax paper on a baking sheet or cutting board and find space for it within your refrigerator. Use a 2 tablespoon portion scoop to scoop the cake into the palm of your hand. Roll and shape into a log shape. Set on prepared baking sheet and refrigerate for 2 hours.
While refrigerating, make the candy clay.
Melt white candy melts according to package directions. Stir in corn syrup until a clay forms. Drop onto a large piece of plastic wrap and wrap tightly. Cool and refrigerate for an hour.
Melt half of the candy melts in a microwave safe bowl according to package directions. Dip cake bites into vanilla almond bark and return to wax paper to set. Refrigerate to harden.
Remove candy clay from refrigerator and remove a small portion. Candy clay is very hard so use a small section. Knead in your hands until smooth. Use cornstarch dusted on a cutting board or your hands if the candy clay begins to stick. Roll to ⅛" thick and cut with a circle cookie cutter. Gently shape the clay over the cake bite. Repeat until all cake bites are covered.
Place black wafers into a resealable plastic bag and microwave for 15 seconds on 50% power and knead. Return to microwave for an additional 15 seconds until smooth. Cut a small corner of the bag and pipe eyes and a mouth onto ghost.