Blueberry Buttermilk Cake (aka another plain cake)

I have to admit it--I'm a blueberry hoarder. Every summer, I make sure that I go blueberry picking at least once (and usually twice), and even though I might make muffins or crumble right then, I make sure that I have several large ziplock bags full of frozen berries in my freezer shortly thereafter. And I find myself somewhat reluctant to use them in the first cooler months--I start to envision a blueberry-less February, and I don't want to do that to myself. (I know, of course, that blueberries are available in the frozen foods department of any grocery store, but I'm always more attached to the berries I've picked myself--they're tangible proof that it was summer once and therefore must be again.) By late winter and early spring, though, I'm a bit more profligate with the berries, and by this time of year, I'll bake with them weekly--blueberry season, after all, is actually in sight, if still several months away. And it's even more heartening this year to see that there are berries developing on the biggest of my three baby blueberry bushes. (I'm thinking I might put a couple more in, if I can figure out where--who needs all that lawn, anyway?)

I was thinking about making blueberry muffins today, but I wasn't in the mood for either of my usual blueberry muffin recipes. And I'd seen this recipe up on Smitten Kitchen last week, as raspberry buttermilk cake, and had noted it as something I might want to make eventually, but I didn't think too much about it. But today, I was flipping through the June issue of Gourmet and saw the recipe again, and this time, something stuck--probably it was when I realized that this would be an excellent cake with blueberries as well as raspberries.

This cake is easy, easy, easy, and it's also nice in that it's not that bad for you. It has a half stick of butter and a single egg in the whole cake. You could even, maybe, call it a somewhat virtuous cake (unless, of course, you feel compelled to eat half of it at one sitting.). And it's definitely delicious. It's not quite a one bowl cake, but it's 2 bowls, only one of which really gets dirty, and one measuring cup for the buttermilk. I was generous with the blueberries on top, and I put some lemon zest in the batter, since I'm a big fan of the lemon/blueberry combo (Exhibit A). It took all of 15 minutes (if that) to put together, and it was out of the oven and cool enough to eat in less than an hour.

As for the serving size, I want to quote Laurie Colwin, who wrote this in her chapter on "How to Make Gingerbread" in her wonderful book of food essays, Home Cooking:

"This little three-layer cake will feed six delicate, well-mannered people with small appetites who are on diets and have just had a large meal, or four fairly well-mannered people who are not terribly hungry. Two absolute pigs can devour it in one sitting--half for you and half for me--with a glass of milk and a cup of coffee and leave not a crumb for anyone else."

I won't say that that's what Alex and I did this afternoon. But I will say that there is perhaps a third of the cake left, and I know already that it's lovely with tea, so I won't guarantee it lasting past tomorrow.

Blueberry Buttermilk Cake
Adapted from Gourmet, June 2009

The original recipe called for raspberries, and I obviously used blueberries. Any type of berry seems like it would suffice. I'm also contemplating how this might work with rhubarb instead of berries. It feels like a generally flexible recipe, so I'll bet lots of variations could work.

Makes one thin 9-inch cake--see note on number of servings above.

1 cup all-purpose flour (I used 1/3 whole wheat pastry flour)
1/2 teaspoon baking powder
1/2 teaspoon baking soda
1/4 teaspoon salt
1/2 stick unsalted butter, softened
2/3 cup plus 1 1/2 tablespoons sugar, divided
1/2 teaspoon pure vanilla extract
1/2 teaspoon finely grated lemon zest (optional)
1 large egg
1/2 cup well-shaken buttermilk
1 cup fresh berries (I used 1 1/2 cups frozen blueberries.)

Preheat oven to 400°F with rack in middle. Butter and flour a 9-inch round cake pan.

Whisk together flour, baking powder, baking soda, and salt and set aside. In a larger bowl, beat butter and 2/3 cup sugar with an electric mixer at medium-high speed until pale and fluffy, about two minutes, then beat in vanilla and zest, if using. Add egg and beat well.

At low speed, mix in flour mixture in three batches, alternating with buttermilk, beginning and ending with flour, and mixing until just combined.Spoon batter into cake pan, smoothing top. Scatter berries evenly over top and sprinkle with remaining 1 1/2 tablespoons sugar.

Bake until cake is golden and a wooden pick inserted into center comes out clean, 25 to 30 minutes. Cool in pan 10 minutes, then turn out onto a rack and cool to warm, 10 to 15 minutes more. Invert onto a plate.

(Deb and many of her commenters said their cakes baked in 20 minutes. Mine did not. At 25 minutes, the middle was still a bit jiggly, so I left it in for 5 more minutes, and it was perfect.)