Coat an 8-inch round cake pan with cooking spray. Set it aside.

Add the butter to a medium saucepan set over medium-low heat. Once the butter has melted, add the marshmallows and cook, stirring constantly, until the marshmallows are melted. Stir in the vanilla extract and then the Rice Krispies cereal until the cereal is well coated.

Transfer the mixture into the prepared cake pan an press it firmly against the inside edge of the pan to form about a 1-inch crust. Let it cool while you prepare the filling.

Add the butter and pumpkin pie spice to a medium saucepan set over medium-low heat. Once the mixture has melted, add the marshmallows and cook, stirring constantly, until the marshmallows are melted. Stir in the orange food coloring then stir in the Rice Krispies cereal until the cereal is well coated.

Press the mixture firmly inside the crust border, pushing it down to compact it, and allow it to cool completely in the pan. Once cooled, place a serving plate on top of the pan and invert the pan. Slice the pie into wedges and top with a dollop of whipped cream (optional).

In place of the regular marshmallows and the pumpkin pie spice, you can use the Pumpkin Spice Mallows for the pumpkin filling.