Before starting, make sure all ingredients are at room temperature.
Whisk all of the dry ingredients together.
Whisk all of the wet ingredients together in a separate bowl.
Pour the wet ingredients into the dry ingredients.
Use a silicone spatula or mixing spoon (not a whisk) to mix only until the flour is absorbed. The batter does not need to be perfectly smooth; lumps are okay to avoid overmixing!
If using mix-ins, fold into the batter, stirring as little as possible.
Transfer to your prepared baking pan and bake immediately.