On a recent visit to the farmers market I got beautiful blueberries, and was wondering what to do with them (besides popping them in my mouth) when I remembered I wanted to try making this buckle. Upon tasting it, my baker friend at work called this "the best blueberry buckle I've ever had."
The Smitten Kitchen Cookbook calls it a blueberry cornmeal butter cake, and describes it as the place where a blueberry buckle meets Southern cornbread. If you don't like cornbread, don't be put off. I'm not a fan of the squidgy, gritty squares that come on the side of plates in restaurants either, but this is different. The texture is more of a background note, and lends itself well to wonderfully crisp edges. The buckle is moist and lightly sweet, and the blueberries picked the morning of the market gave it a wonderful, summery flavor. Make it soon while blueberries are in season, and before summer slips away.
I did have one issue with the recipe, and that was the weight measurements. Given the choice between volume and weights, I always pick the latter. Using a scale is more precise, I never lose count of cups or tablespoons, and I don't have to break out said cups. But the buckle was still very liquid in the middle after 35 minutes. A few minutes more didn't help, and it was still not fully set after sitting in the oven with the heat turned off. On my second try I used only volume measurements, but also weighed them as I went, out of curiosity -- some of the grams were way off from what the recipe stated. So, lesson learned: use only volume measurements for this recipe, and I've given only those below.
On a minor note, the streusel topping came out dry and sandy. I wanted nice, big, buttery pebbles that have more crunch and stay on the top like this crumble, so I increased the butter and tweaked the method.
Looking for additional blueberry goodness? Check out my Blueberry Roulade.
Update 6/3/2014: It appears a really hot day can mess with this recipe. When I made this today (the temperature was around 80 degrees), my streusel topping was warm and soft, and in the oven it melted into the top of the buckle batter. So instead of remaining pebbly on top it became part of the buckle and took way longer to finish baking.
If you're making this on a hot day without air conditioning, I recommend putting your streusel dough in the refrigerator for at least 10 minutes to firm up before crumbling it over the buckle batter and baking.
Blueberry Cornmeal Buckle
Adapted from The Smitten Kitchen Cookbook's Blueberry Cornmeal Butter Cake
8 tbs unsalted butter, at room temperature
1 cup unbleached all-purpose flour
½ cup cornmeal
2 tsp baking powder
½ tsp coarse salt
1 cup sugar
2 large eggs
¼ tsp pure vanilla extract
¼ tsp grated lemon zest
⅓ cup sour cream
2 cups blueberries, washed and patted dry
For the streusel:
½ cup sugar
6 tbs all-purpose flour
2 tbs cornmeal
¼ tsp cinnamon
¼ tsp coarse salt
4 tbs unsalted butter, at room temperature
Preheat the oven to 350°. Line the bottom of an 8-inch square pan with parchment paper, then coat the bottom and sides with cooking spray.
Stir together the flour, cornmeal, baking powder, and salt in a bowl. In another bowl using an electric mixer, beat together the butter and sugar for 2 minutes, until pale and fluffy. Beat in the eggs one at a time, then add the vanilla and lemon zest. Add one-third of the flour mixture and beat just to combine. Then beat in the sour cream, followed by another third of the flour mixture. Scrape down the sides and bottom of the bowl (unless you have this awesome beater blade like I do). Stir the blueberries into the remaining flour, and gently fold that into the batter by hand, using a spatula. Scrape the batter into the square pan.
Stir together all the dry streusel ingredients in your mixer bowl (no need to wash in between), then use the mixer to beat in the butter just until combined. Gather a handful of the streusel mixture and squeeze into a fist, then lightly break it up with your fingers while scattering across the top of the buckle. Repeat with the rest of the streusel mixture.
Bake the buckle for 35 minutes, until the top is golden and the edges are lightly browned, and a tester inserted into the middle comes out clean. Let the buckle sit in the pan for 5 minutes, then run an offset spatula around the edges to loosen them. Gently flip the buckle out onto a plate and peel off the parchment. Flip it right-side-up again onto a cooling rack, and be gentle because the buckle is still fragile while warm. The buckle can be stored covered at room temperature for a day; afterwards, move it to the fridge in an airtight, covered container.