Prepare the Pan: Grease a 9x13 inch baking pan with butter using a paper towel to spread it evenly across the bottom and sides.

Melt Butter: In a large saucepan, set the heat to medium and add 7 tablespoons of butter. Stir until melted and bubbly, about 3-5 minutes.

Add Marshmallows: Once the butter is melted, add 10 ounces of miniature marshmallows. Stir for 2-3 minutes until fully melted.

Mix Cereal: Remove from heat and quickly add 8 cups of Fruity Pebbles cereal, stirring vigorously to coat evenly.

Press Mixture: Transfer to the prepared pan, dampen your fingers with cool water, and press the mixture evenly into the pan.

Let Set: Allow to cool completely at room temperature for at least 30 minutes.

Cut into Squares: Once set, remove from pan and cut into approximately 1-inch squares.