Preheat the oven to 180C/350F. Grease a 9-inch cake pan and set aside.
In a mixing bowl, mix together your flour, baking powder, salt, pumpkin spice, and cinnamon. Add the sugar, oil, pumpkin puree, maple syrup, vanilla, and water, and mix until combined.
Transfer to the greased cake pan. Bake for 30 minutes, or until a skewer comes out just clean.
Remove from the oven and let cool completely, before frosting.
Notes
* You can use white sugar, brown sugar, coconut sugar, or sugar free substitutes. Use a mix of them or just one kind. If you use brown sugar or coconut sugar, your cake will be darker in color. TO STORE: If your cake is unfrosted, you can store it at room temperature, covered, for up to 5 days. If frosted, or if you'd like the cake to keep longer, store it in the refrigerator for up to 2 weeks. Let the refrigerated cake sit at room temperature for 30 minutes before serving. TO FREEZE: Place slices of cake in a freezer friendly container and store in the freezer for up to 6 months. Thaw overnight in the refrigerator.