Start by adding the dry ingredients into a big mixing bowl, flour, baking powder, baking soda, cream of tartar, salt, cinnamon, nutmeg, and ginger. Mix with a whisk until combined and set aside.
Into a separate big mixing bowl, add the room temperature butter, brown sugar, and granulated sugar. Cream the butter and sugar with an electric hand mixer until the mixture is creamy and light.
Add the egg, vanilla extract, and the pumpkin puree, and mix until combined.
Add half of the flour mixture and mix until almost combined. Add the other half and mix until just combined. Cover the bowl with plastic wrap and let the dough rest in the fridge for at least 30 minutes.
Preheat an oven to 180c (350f). In a small mixing bowl, add the cinnamon and sugar and mix until combined.
Use a cookies scooper to scoop out the cookies, and roll each cookie into a ball, and roll each cookie dough into the cinnamon-sugar mixture, making sure that the cookie dough is covered with cinnamon sugar.
Place the cookie dough balls onto a parchment paper-lined baking sheet, and bake in a 180c (350f) preheated oven for 11-12 minutes. Let the cookies cool for 5 minutes, and then transfer them to a wire rack to cool completely.