Once butter is melted, add vanilla and 6 cups of marshmallows. Melt the marshmallows slowly.
Right before the marshmallows are fully melted, add milk and the other 2 cups of marshmallows. Stir until the added marshmallows are starting to melt. (we don't want them fully melt so you will have a lumpy fluff)
Add the Rice Krispie Cereal. Stir until the cereal is fully coated with the marshmallow fluff.
Spray the molds with non-stick spray.
Using a spoon add some treat mixture to the mold and use a spatula (sprayed with non-stick spray) to press the treats into the molds.
Gently remove the treats from the molds and place on wax paper. Work quickly to form all the treats before they cool.
Line a large cookie sheet with wax paper. Lay some figures on the sheet leaving room between them.
Cover the areas with cling wrap that you don't want to be the color you are using. Then spray the area. (See post for clearer instructions.)
Repeat #9 for each color spray. Remember to cover the areas you don't want spray.
Allow to air dry before storing.
If you are making these for a party, I highly suggest do these the day before to allow for then to sit out and air dry.
Notes
Adding color to the treats is optional. It is ok to leave them the natural rice krispie treat color if you wish.