1. Line 12 (2-1/2-inch) muffin-pan cups with paper or foil bake liners. Set aside. In a large saucepan melt butter over low heat. Add marshmallows and stir until completely melted. Remove from heat. Stir in vanilla and strawberry extract. Add Kellogg's Rice Krispies cereal. Stir until well coated.
2. Evenly divide warm mixture into prepared cupcake molds. Using buttered hands, gently press into molds, leaving tops slightly rounded.
3. Decorate with frosting, sprinkles and/or candies. Serve immediately or store uncovered in refrigerator for up to 12 hours Remove from refrigerator 1 hour before serving.