Whisk 1/2 cup white sugar, melted butter, and brown sugar together in a large bowl. Add pumpkin puree and vanilla extract; whisk until smooth.
Combine flour, 1 1/2 teaspoons cinnamon, pumpkin pie spice, salt, baking soda, and baking powder in a separate bowl.
Mix flour mixture into the sugar-butter mixture; stir until just combined. Fold in chocolate chips gently. Cover dough with plastic wrap and chill for 30 minutes.
Preheat oven to 350 degrees F (175 degrees C). Line a baking sheet with parchment paper or a Silpat(R) baking mat.
Roll 1 1/2 tablespoons of chilled dough into a ball. Repeat with the remaining dough.
Combine the remaining 1/2 cup white sugar, 3/4 teaspoon cinnamon, and cayenne pepper in a small bowl. Roll dough balls completely in the spicy cinnamon-sugar. Place on the prepared baking sheet, at least 2 inches apart, and slightly flatten the tops.
Bake in the preheated oven until edges are golden and cookies appear under-baked, about 9 minutes. Remove from oven and immediately place candy-coated chocolate pieces on top. Cool on the baking sheet for 10 minutes. Transfer to a wire rack to cool completely.