Butter a 9" x 13" baking dish or pan. Set aside.

Lightly spoon cake mix into measuring cup. Sift into small bowl. Set aside.

Melt butter in a 4 quart sauce pot over medium heat.

Add marshmallows; cook and stir just until marshmallows are melted and smooth.

Add cake mix and stir until well blended. Turn off heat and add the crispy rice cereal. Stir until well blended. Work fast because the marshmallow mixture will start to stiffen very quickly.

Stir in 1/4 cup (4 tablespoons) sprinkles. Note: Do not add the sprinkles until after everything else has been mixed. If using 'jimmies', work quickly and stir just until incorporated. Jimmies melt easily. "Confetti" types of sprinkles hold up much better and will not melt.

Immediately put the cereal mixture into the buttered baking dish or pan. Press mixture in pan evenly. I usually lightly butter my hands and press the mixture around in the pan. Be careful because it is HOT. A lightly buttered large mixing spoon can also be used to spread the mixture.

Sprinkle the remaining 2 tablespoons of sprinkles over the top and gently press them against the marshmallow mixture. Just lightly pat them, you don't want to squish them.

Set aside to cool. Cut as desired.