Place Oreo's in food processor and process to coarse texture. Add peppermint patties and process to coarse texture.
Coat a 10 in. springform pan with cooking spray, add cookie mixture and press down gently to coat bottom and up 1/2 in. on the sides.
By spoonfuls, add ice cream. Use back of a spoon to smooth ice cream evenly on the top.
Cover with foil and freeze overnight.
Place vanilla wafers in food processor and blend until smooth. Place in a sealed bag until needed and store at room temperature.
Remove rim of springform pan and place cake on serving platter. On one side of cake, slowly pour vanilla wafer crumbs to form a mound, or "anthill."
Arrange "ants" on cake using one chocolate covered almond for each body and one chocolate covered caramel for each head. Pipe on eyes and legs with gel.
Garnish with candy corn.