Butter a 9 x 9 inch baking dish.
Spread pumpkin puree on a stack of paper towels and let it sit for about 5-10 to draw out moisture.
¼ cup pumpkin puree
In a large saucepan melt butter over medium heat stirring frequently. Add pumpkin and continue heating and stir until well mixed.
4 Tablespoons butter
Add in marshmallows and continue heating, stirring frequently until marshmallows are melted.
12 ounces marshmallows
Add in pumpkin pie spice and stir in until evenly mixed. If a deeper orange color is desired add a few drops of orange food coloring.
1 teaspoon pumpkin pie spice, orange gel food coloring
Remove from heat and fold in Rice Krispies.
6 cups Rice Krispies cereal
Evenly press mixture into prepared pan.
Allow to cool.
While the Rice Krispies mixture is cooling place white chocolate chips in a double boiler, or a heat safe bowl over a small pot of water. Heat over medium/high heat stirring frequently until melted and smooth.
½ cup white chocolate chips
Place in a piping bag and gently drizzle across Rice Krispies treats.
Allow to cool before cutting. Cut into 9 squares and serve.
Store in an airtight container.