How about a Progressive [pun intended] Potluck Dessert? Send the gang over from the Typical-White House for this delight which will really make them purr:
Kitty Litter Box Cake.
Recipe courtesy fabulous foods.com (with modifications):
1 spice or German chocolate cake mix
1 white cake mix
2 large packages vanilla instant pudding mix, prepared
1 large package vanilla sandwich cookies
green food coloring
12 small Tootsie Roll candies
1 new used kitty litter pan
1 new used kitty litter pan liner
1 new used pooper scooper