Melt the Butter: Add the butter to a large pot and melt it over low heat. Keep the heat low so the butter melts gently without browning.
4 tablespoons butter
Melt the Marshmallows: Add the marshmallows to the pot and stir until they are completely melted and smooth. Keep stirring so the mixture does not stick or burn.
1 10- ounce bag large marshmallows
Color the Mixture: Remove the pot from the heat. Add the yellow food coloring first and stir well. Add the red food coloring one drop at a time, stirring as you go, until the mixture turns pumpkin orange.
12 drops yellow liquid food coloring, 4 drops red liquid food coloring
Add the Cereal: Pour in the Rice Krispies cereal and stir until the cereal is fully coated with the orange marshmallow mixture. Work fairly quickly because the mixture gets harder to shape as it cools.
6 cups Rice Krispies cereal
Shape the Pumpkins: Line a baking sheet with parchment paper. Once the mixture is warm but cool enough to handle, coat your hands generously with vegetable oil or melted butter. Scoop and roll the mixture into 12 balls, recoating your hands after each pumpkin so the mixture does not stick.
¼ cup vegetable oil or melted butter
Add the Stems: While the pumpkins are still warm, gently press one Mini Rolo into the top of each pumpkin. This makes the stem and helps the treats look like pumpkins instead of suspicious orange cereal balls.
12 Mini Rolos
Add the Leaves: Press one green M&M next to each Mini Rolo to make a leaf. Push it in gently so it sticks without smashing the pumpkin.
12 green M&M’s
Let Them Set: Let the pumpkins cool at room temperature until firm. Serve them the same day, or store them in an airtight container at room temperature.