There is nothing more satisfying than testing a recipe twelve times and finally getting it right. Okay, maybe not twelve times, but in this case, six times to get it right. I know, I know, why did I need to make this six times? Well, I basically failed to follow my own rule: make a recipe once the way it was written, THEN modify to taste. I was overeager and just figured I could skate by changing pan sizes, adjusting temperatures, and switching out ingredients before I really knew what the cake was meant to be. At least now I can say that this recipe has been thoroughly vetted for your consumption.
The idea for the cake came from wanting to use up the bounty of blueberries that have been coming out of our tiny garden patch and turn them into a cake for my lovely graphic designer. I thought a nice lemon blueberry coffee cake would be just the thing to brighten up her morning. Six versions later, we now have a lemon blueberry crumb cake. I moved the blueberries to the middle of the cake to keep it moist and added extra lemon zest for a bright flavor. Topped with buttery crumbs and a thick dusting of powdered sugar, this cake has finally come together. In my opinion, the only way to make this cake any better would be to double the crumbs. The crumb cake of my youth is pretty much an equal ratio of crumb to cake, but perhaps that’s an East Coast thing. Hmm… maybe I should make that seven recipe tests…
Lemon Blueberry Crumb Cake (modified from The Essential Baker)
1/4 cup granulated sugar
1/4 cup dark brown sugar, packed
1/2 tsp. cinnamon
1/8 tsp. salt
6 Tbls. unsalted butter (3/4 stick), melted
1 cup all-purpose flour
12 Tbls. unsalted butter (1 1/2 sticks), room temperature
3/4 cup granulated sugar
2 large eggs, room temperature
1/2 tsp. vanilla extract
2 Tbls. lemon zest (3 small lemons)
1 3/4 cups all-purpose flour
2 tsp. baking powder
1/2 tsp. baking soda
1/4 tsp. salt
1/2 cup plain yogurt
1 cup fresh blueberries
Combine granulated sugar, dark brown sugar, cinnamon, and salt in a small bowl. Melt butter in a microwave safe dish and stir into sugar mixture. Mix in all-purpose flour until a crumbly dough forms. Set aside.
Preheat oven to 350°F and move oven racks to the middle. Grease, flour, and put parchment on the bottom of a 8-inch square pan.
In a medium bowl, whisk together flour, baking powder, baking soda, and salt. Set aside. Cream butter & sugar in a stand mixer (or a large bowl and hand mixer) for several minutes until light and fluffy. Add eggs, one at a time, and scrape down bowl between each addition to incorporate. Add vanilla and lemon zest and mix well. In three stages, alternating between the dry ingredient and the yogurt, add each to the butter mixture, beginning and ending with the dry ingredients. Scrape down the bowl between each addition and mix just until it comes together.
Layer half the batter in the bottom of the pan, scatter blueberries on top, and spread the rest of the batter over that. Scatter crumb topping evenly over batter and place in oven for 40-45 minutes until a tester comes out clean and top is golden brown. Cool on a wire rack and top with a healthy dose of powdered sugar before serving.