Preheat the oven to 350°F (175°C) and grease two 8-inch cake pans.
In a bowl, whisk together flour, baking powder, baking soda, cinnamon, nutmeg, ginger, and salt.
In another bowl, beat sugar, brown sugar, and eggs until smooth. Add pumpkin puree, oil, and vanilla.
Gradually mix the dry ingredients into the wet ingredients.
Pour the batter evenly into the prepared pans. Bake for 35-40 minutes, or until a toothpick comes out clean.
Let the cakes cool in the pans for 10 minutes, then transfer to a cooling rack to cool completely.
To make the frosting, beat butter, powdered sugar, cinnamon, ginger, milk, and vanilla until smooth and fluffy.
Frost the cooled cakes generously, and sprinkle with cinnamon for garnish.