Using butter or cooking spray, prepare a 9 x 13 pan or line with parchment paper.

In a medium to large saucepan, melt the butter over low heat.

Add the marshmallows and stir until completely melted. Remove from heat.

Add the Rice Krispies cereal and stir until cereal is well coated.

Butter your hands or use wax paper to press the mixture firmly and evenly into the pan. Allow to cool.

Line a cutting board or tray with parchment paper or wax paper.

Cut rice krispies into approximately 1" square bites and place on prepared tray. Place in freezer for 15 minutes.

Heat chocolate by microwaving for 1 minute, stirring and repeating until melted.

Using a fork dip each bite into chocolate to completely coat. Shake off excess and return to tray.

You can optionally decorate with sprinkles or candy decorations.