Whisk gelatin, corn syrup, vanilla, and boiling water in the bowl of a stand mixer until the gelatin dissolves. Using the paddle attachment, beat in the cocoa and powdered sugar on medium speed, 1 cup at a time, until the dough comes together. It will be soft and sticky.
Transfer dough to a work surface and knead, adding more powdered sugar as necessary until the dough is smooth and pliable and slightly tacky (and able to be rolled out). I only needed about 1/4 cup of extra powdered sugar, but you may need up to 1 cup.
Divide the dough in half. Wrap one half in plastic wrap. Roll out the other half to between 1/8-1/4 inch thick. Use a small football shaped cookie cutter (mine was an oval fondant cutter) to cut out shapes. You can also use a heart cutter, perfect for Valentine’s Day!
Place shapes on a wax paper lined cookie sheet. Repeat with second half of dough.
Using a toothpick and a bit of white food coloring, make the laces on top of each football. Do not use too much, the food coloring will not dry unless it is very light.
Let the candies dry at room temperature, uncovered for about 24 hours, or until hard.