Prep: Preheat the oven to 425°F. Lightly grease a 7x11 rectangular baking dish.
Mix the wet and dry ingredients separately: Whisk the dry ingredients together in a large bowl. Whisk the wet ingredients together in a separate bowl or measuring jug.
Combine batter: Pour the wet ingredients into the bowl with the dry ingredients. Using a spoon or spatula, fold together JUST until combined - do not overmix.
Bake: Pour the batter into the prepared baking dish. Bake for 20-25 minutes or until a toothpick inserted into the middle comes out clean. Cool 10-15 minutes in the pan on a wire rack and serve warm cut into squares.