2 tablespoons sugar plus 1 teaspoon cinnamon, mixed
Place cereal in large bowl and set aside.
Melt butter with corn syrup and marshmallows over medium high heat.
Stir in pudding mix, vanilla, and pumpkin spice. When ingredients are well mixed and smooth, remove from heat and pour over cereal. Mix with rubber spatula to combine.
Scrape cereal mixture into greased 8×8 inch pan. Allow to cool slightly. Spread frosting on top. Sprinkle with cinnamon-sugar mixture. Allow to set 10-15 minutes, then cut into bars. Store in airtight container.