And then, because I've made this cake so many times I know it like the back of my hand, I decided to kick it up a notch. Grapefruit's in season now, and I had a lovely ripe one sitting on the counter, so I decided to add some grapefruit to the batter. And because brown sugar and grapefruit pair wonderfully, I replaced half the sugar with brown sugar. These little tweaks were an experiment that definitely paid off.
And, I got to use my pretty new mixing bowl that Hannah got me! Thanks, Hannah!
Cream your butter and sugar together: 2 sticks of butter, one cup of white sugar, and one cup of brown sugar. It should have the consistency of wet sand.
Add five large eggs, mixing thoroughly after each egg.
Sift together two cups of flour and one teaspoon of baking powder, then add to the wet ingredients.
Rap the pan on the counter a few times to knock out the air bubbles and then put it in the oven.
It'll take about 45-55 minutes to bake (my oven runs a little cool I think, so after fifty minutes I turned off the heat and let it sit in the oven with the door closed for another ten minutes or so just to finish firming up). The cake is done when the top is golden brown and the edges start to pull away from the pan.
Gently slide a knife between pan and cake and then turn it over onto a plate. Let it cool for a few minutes before sprinkling with powdered sugar.
Go for extra credit: You can make a compote to serve alongside the cake, although it is amazing on its own. Supreme your remaining grapefruit and toss with three tablespoons of brown sugar, then let it sit while the cake bakes. A chiffonade of fresh mint on top wouldn't hurt.