Melt the 3 tablespoons of butter in a large saucepan over low heat. Add in the 6 cups of mini marshmallows, stirring constantly until fully melted and smooth, about 3-5 minutes.

Add 8 cups of Rice Krispies to the melted marshmallow mixture, stirring quickly to coat all the cereal evenly. Allow to cool for about 5 minutes.

Add a few drops of food coloring to the mixture and stir well until evenly distributed. Mix in 1 cup of chocolate chips if desired.

Grease a 9x13 inch pan lightly with butter and transfer the warm mixture into the pan, pressing it down firmly.

Once flattened, allow it to cool for about 30 minutes at room temperature.

Use a heart-shaped cookie cutter to cut out treats. Gently lift each heart-shaped treat from the pan.

Melt some chocolate and drizzle over the heart-shaped treats, then sprinkle with colored sprinkles or coconut flakes.

Let the decorated treats set for an additional 10-15 minutes before serving.