Spray 9x13 inch baking dish with cooking spray.
In a large saucepan, melt butter over medium-low heat.
Add marshmallows to saucepan and stir until melted.
Turn off heat and add in Pumpkin Spice Cheerios, cinnamon, nutmeg, and ginger. Stir until Cheerios are completely coated in marshmallow.
Fold in white chocolate chips.
Pour mixture into prepared baking dish and let sit for about an hour to cool and harden.
Cut into squares.