Grease and flour a 9-inch square baking pan and line with parchment paper, if desired.
Pre-heat oven to 350°F.
In a medium bowl, whisk together the flour and baking powder first, then add all of the other cake ingredients.
Using an electric mixer, beat together quickly; do not over-mix this batter; it is still a pretty thick batter and if it is mixed too much, the gluten in the flour will begin to develop and toughen the texture of your cake.
Spread the batter evenly into the prepared pan, place in the pre-heated oven and bake for 35 to 40 minutes or until a toothpick inserted in the center comes out clean.
Be careful not to overbake this cake; check it early, because it can appear quite pale on top and still be fully baked; it does not need to brown on top to be baked fully.
Remove from the oven and cool, in the pan, before serving.