Line a 12 x 18-inch cookie pan with plastic wrap, allowing wrap to overhang pan edges, about 2 inches. Spray plastic wrap with vegetable pan spray.
In Dutch oven or very large saucepan, melt butter over low heat. Add marshmallows; stir until completely melted and smooth. Remove from heat. Stir in cereal, dried fruit and, if desired, pecans; mix thoroughly. Firmly press cereal mixture into prepared pan. Cool completely, at least 30 minutes.
Carefully remove treat from pan by lifting out plastic wrap to cake board or other flat surface.
Cut rice cereal treat using cookie cutters.
Set out assorted icing and sprinkles.
Decorate as desired with icing, Sparkle Gel and sprinkles.