Step 1: Grease two 9-inch round cake pans thoroughly with butter.
Step 2: Melt 4 tablespoons of butter in a large pot over low heat, then add 10 ounces of mini marshmallows, stirring until melted.
Step 3: Tint the mixture with pink or red food coloring and add optional fruit extract.
Step 4: Stir in 5 cups of rice cereal and the mini chocolate chips until well coated.
Step 5: Press the pink mixture into the center of the prepared pans, forming a 7-inch circle in the middle.
Step 6: In a clean pot, melt the remaining 2 tablespoons of butter and 3 cups of marshmallows.
Step 7: Tint the mixture with green food coloring and stir in the remaining 3 cups of rice cereal.
Step 8: Press the green mixture into the ring around the pink centers. Let cool, then slice each pan into 8 wedges.