Start by preheating your oven to 425°F and getting your pan ready. Line an 18x13-inch baking sheet with parchment paper and give it a light spray with cooking spray.
In a medium bowl, mix your dry ingredients. Whisk together the flour, brown sugar, baking powder, spices, baking soda, and salt until they're well combined.
Pour the dry mixture into the wet ingredients and whisk until they're just combined. Don't use an electric mixer here, and don't worry about small lumps - they'll bake out.