Heat the marshmallows and 3 Tbsp butter in a large mixing bowl for 90 seconds or until the marshmallows get puffy.
Mix in a couple drops of food coloring and thelemon extract.
Mix in the Rice Krispies cereal.
Grease the bottom of a 9x9 baking pan with 1/2 tsp butter.
Turn the Rice Krispies mixture out onto the pan. Rub a little butter on your hands, or spray with nonstick spray, then press the mixture into the bottom of the pan.
Place in the freezer for about 30 minutes, until firm.
Slice into squares and enjoy!