Preheat the oven to 425 degrees F. Bake the pumpkin pie mix for 30 minutes, then remove, stir, and let cool. In the meantime, make the pumpkin syrup by combining ½ cup water, ½ cup granulated sugar, and ½ teaspoon pumpkin pie spice in a pot over medium heat. Bring to a boil, then lower to a dancing simmer and let cook, stirring occasionally, for 10 minutes, or until the sugar is completely dissolved. Let cool.