Coat your fingers and palms with butter, and use your hands to scoop out a little bit of the cereal treat mixture at a time. Mold into the shapes of nigiri (ovals that are flat on the bottom), and onigiri (triangles with rounded corners). To make uramaki, (round, sliced, filled rolls), form a wide, flat rectangle on a cutting board. Slice off the edges for a sliced look, and slice into 1 inch strips. Fill the strips with candy and roll, trimming the ends and pressing together to seal. Work with the cereal treats while they are warm, and apply pressure to ensure they keep their shape. If the mixture cools too rapidly, turn on the heat again to low for a minute or two.