Citrus Yogurt Cake

This is my go-to loaf cake for any occasion or no occasion at all. It's moist, the slices hold up, and the flavor is delicious. I have made it with all different kinds of citrus: lemon, orange, grapefruit (as in the original), lime, key lime, tangerine, and even kumquat. I have made it with 100% all-purpose flour, almost 100% whole wheat pastry flour, and usually a mixture of the two. I have made it with nonfat, full-fat, and Greek yogurt. I once made it dairy-free and it was still great. Sometimes I add random berries (raspberry, blueberry) or other fruit (pear) into the batter. This cake, it never disappoints.

A version of the very adaptable citrus yogurt cake with lemon
and poppyseed.

The instructions that follow show the modifications I made for high-altitude baking (7000 ft). Since not every cake works like a charm in this rare air, when I find one I like, I stick with it. I tested a "pound cake"-type recipe which was way less healthy than this one, and didn't even like it half as much. This is the one.

Lemon poppyseed version basking in the sun.

Sometimes I add random berries or fruits. One
of the two loaves pictured here (I can't recall
which one) was made dairy-free using a mix
of vinegar and water instead of yogurt.

Experiment with whatever citrus you feel like. The original,
with grapefruit, is awesome. So are orange and lime and lemon
versions.

Zesting kumquats...not recommended. Plus, they don't make
very much juice for the glaze. Worth doing once for the novelty.

Why did I once make it with kumquats? Because we have a kumquat tree. I know that's not news if you live in southern California, where they're essentially considered ornamental and grow everywhere, but where we live, citrus does not survive the winter. We kept our dwarf tangerine and kumquat trees in large pots for a couple of years, bringing them outside for the whole summer and indoors all winter. When we built the greenroom, the trees went into the ground, where they are very happy.

Before we built the sunroom/greenhouse, we grew the kumquat tree in a large pot and brought it outside every spring and back indoors for the snowy winter.

Now the kumquat tree lives happily in the ground of the greenroom. It produces lots of kumquats around Christmastime. I personally don't like them...except in cake.

This recipe is definitely worth doubling to make two loaf pans at once. I've also made it into muffins; raise the temperature to 375 and cook for about 25 minutes.

Ingredients Adapted for altitude and other minor changes from Smitten Kitchen. High altitude adjustments shown in blue. For the cake: 1 cup + 1 Tbsp all-purpose flour 1/2 cup whole wheat pastry flour 2 tsp minus 1/8 tsp baking powder 1/2 tsp kosher salt 1 cup + 1 Tbsp plain or Greek yogurt 1 cup minus 1 Tbsp sugar 3 eggs Zest of 2 lemons* 1/4 tsp vanilla extract 1/2 cup vegetable oil For the glaze: 2 Tbsp sugar Juice of 2 lemons (or other citrus fruit) * I'm not fussy with the amount of zest: I zest the two lemons, limes, or tangerines that I then use for the glaze, so there's no waste. If the limes or tangerines are really small, use 3. If using grapefruit, you only need 1. If doing kumquats....don't do kumquats. Just kidding, if you desperately want to use kumquats, you should. Zest a ton of them (see above pic). Preheat the oven to 350 F. Line the bottom of a loaf pan with parchment paper and grease/spray. Sift the flours, baking powder, and salt into a bowl. In a larger bowl, whisk the yogurt, sugar, eggs, zest, and vanilla. Pour the dry ingredients into the wets in a few small batches, gently whisking between each addition. This is the weird step: fold the vegetable oil into the batter with a spatula. Get it as well-incorporated as you can. Pour the batter into the loaf pan and bake for 50 minutes before beginning to check on it. Use a skewer or cake tester in the center and remove from the oven when it comes out clean. I find that the sides of the cake brown alarmingly while the inside is still wet, but it always comes out great in the end. Right after the cake comes out of the oven, make the glaze: cook the juice of 2 lemons (or 2 limes, or 2 tangerines, or 1 grapefruit, or 2 oranges) on high heat with 2 Tbsp sugar. Let it boil and bubble for a few minutes until it gets just a little thick, but do not let it burn.  Now, you can choose to leave the cake in the pan and poor the glaze over, or get the cake out and add the glaze. My vote is to leave it in, to minimize glaze loss. Whatever you do, don't skip this glaze: it's the best. It is a tart, tangy zing on the tongue against the sweet and mild cake. Yum.