1 spice or German chocolate cake mix
1 white cake mix
2 large pkg vanilla instant pudding mix, prepared (I like Bird's® dessert mix)
1 large pkg vanilla sandwich cookies
green food coloring
12 small Tootsie Rolls®
1 new kitty litter pan
1 new plastic kitty litter pan liner
1 new pooper scooper
Prepare cake mixes and bake according to directions (any size pans).
Prepare pudding mix and chill until ready to assemble.
Crumble white sandwich cookies in small batches in food processor, scraping often. Set aside all but about 1/4 cup. To the 1/4 cup cookie crumbs, add a few drops green food coloring and mix until completely colored.
When cakes are cooled to room temperature, crumble into a large bowl. Toss with half the remaining white cookie crumbs and the chilled pudding. Important: mix in just enough of the pudding to moisten it. You don't want it too soggy. Combine gently.
Line a new, clean kitty litter box. Put the cake/pudding/cookie mixture into the litter box.
Put three unwrapped Tootsie rolls in a microwave safe dish and heat until soft and pliable. Shape ends so they are no longer blunt, curving slightly. Repeat with 3 more Tootsie rolls bury them in the mixture. Sprinkle the other half of cookie crumbs over top. Scatter the green cookie crumbs lightly on top of everything -- this is supposed to look like the chlorophyll in kitty litter.
Heat 3 Tootsie Rolls in the microwave until almost melted. Scrape them on top of the cake; sprinkle with cookie crumbs. Spread remaining Tootsie Rolls over the top; take one and heat until pliable, hang it over the side of the kitty litter box, sprinkling it lightly with cookie crumbs. Place the box on a newspaper and sprinkle a few of the cookie crumbs around for a truly disgusting effect!