Preheat the oven to 350°F (175°C) so the cookies bake evenly and come out golden.
In a large mixing bowl, beat the softened butter and 1 cup of sugar with a hand or stand mixer until light and creamy.
Stir in the pumpkin puree and the egg, and mix until well blended.
In a separate bowl, whisk together the flour, baking soda, cinnamon, nutmeg, salt and baking powder. Gradually add them to the wet ingredients, mixing just until combined.
In a small bowl, combine 1 tablespoon of sugar and 1 teaspoon of cinnamon for rolling.
Scoop tablespoon-sized amounts of dough, roll each one into a ball, then roll the balls in the cinnamon-sugar until well coated.
Place the balls on a lined baking sheet, a couple of inches apart, and bake for about 10–12 minutes, until the edges begin to firm up.
Let the cookies cool on the baking sheet for a few minutes, then move them to a wire rack. Enjoy warm, or store them for later.