Line a small baking dish with parchment paper and set it aside.
In a large saucepan, melt the butter over low heat.
Add the mini marshmallows and stir until fully melted and smooth.
Stir in the pumpkin puree, pumpkin pie spice, orange extract, orange food coloring, and salt until the mixture is evenly colored and combined.
Remove the pan from heat and quickly fold in the Rice Krispies cereal until every piece is coated.
Press the mixture firmly into the prepared dish using a spatula or lightly greased hands.
Let the squares cool at room temperature for 30 minutes before cutting into four pieces.