Cook corn syrup and sugar together in a large saucepan over medium heat, stirring to dissolve sugar. Bring mixture to a boil.
Remove from heat. Stir in peanut butter and food coloring; mix well.
Add cereal; stir until evenly coated.
Pour mixture into greased 15 x 10-inch rimmed baking pan and pat into place.
Using a Christmas tree shaped cookie cutter, press into cereal mixture to cut out shapes. Transfer to waxed paper.
Melt white chocolate over low heat, stirring constantly.
Drizzle or spread over trees and top with sprinkles. Add gumdrop stars.
Recipe Note: Yield size may vary based on cookie cutter used. If Christmas tree cookie cutter does not include a tree stump, gum drops or spice drops may be used to create a stump. Use the melted white chocolate to "glue" candy to base of tree.