Preheat oven to 350°F. Grease and line a 13"x18" half sheet pan with parchment paper. Set aside.
Place all dry ingredients in a large bowl. Whisk together. Add wet ingredients and stir until completely combined. Pour batter into prepared pan. Bake for 25-30 minutes or until toothpick inserted in middle comes out clean. Let cool.
For the frosting:
Place cream cheese and butter in a large bowl. Beat with electric mixer until creamy. Add vanilla. Gradually add sugar. Beat on low until combined, then turn up to medium and beat for about a minute. Frost cooled pumpkin bars. Decorate with candy pumpkins. Slice into 24 bars.
Video
Notes
What if I don't have pumpkin pie spice? To make 2 teaspoons pumpkin pie spice, use 1 ½ teaspoons cinnamon, ½ teaspoon allspice, ½ teaspoon ground ginger, ½ teaspoon allspice and ½ teaspoon ground cloves.