I bought some really yummy-looking blueberries at the local farmer's market and I also needed to a bring a dessert to my tennis league, so this recipe seemed like a perfect fit. I found the recipe online and chose it because it used a LOT of blueberries plus it had a nice crumb streusel. This was simply spectacular. A++
Recipe adapted from www.browneyedbaker.com
1/2 cup flour
1/2 cup light brown sugar
2 tablespoons granulated sugar
1/2 teaspoon ground cinnamon
1/4 teaspoon ground nutmeg
1/8 teaspoon salt
1/4 cup unsalted butter, softened
For the Cake:
1&1/2 cups flour
1/2 tablespoon baking powder
10 tablespoons unsalted butter, softened
2/3 cup granulated sugar
1/2 teaspoon salt
1/2 teaspoon grated lemon zest
1/2 tablespoon vanilla extract
2 eggs, at room temperature
4 cups fresh blueberries
To make Topping: With an electric mixer, combine the flour, sugars, cinnamon, nutmeg, and salt on low speed until well combined, about 45 seconds. Add the butter and continue to mix on low speed until the mixture resembles wet sand, about 2 minutes. Transfer to a small bowl and set aside.
To make Cake: Adjust oven rack to lower-middle position and preheat oven to 350ºF. Grease a 9" round cake pan or a 10" springform pan (that's what I used) and grease the bottom and inside.
In a small bowl, whisk together the flour and baking powder; set aside. Using an electric mixer, cream together the butter, sugar, salt, and lemon zest at medium-high speed until light and fluffy, about 3 minutes. Add the vanilla and beat until combined, about 30 seconds. Reduce mixer speed to medium and add eggs one at a time; beat for 5-10 seconds, scrape sides, and continue to beat until fully incorporated. Reduce mixer speed to low, then gradually add flour mixture and beat until flour is almost completely mixed in, about 20 seconds. Use a rubber spatula to finish mixing (the batter will be very thick). Gently fold blueberries into the batter.
Transfer batter to the prepared pan. Squeeze a handful of streusel in your hand to form a large clump; break up the clump and sprinkle evenly over batter. Repeat with remaining streusel.
Bake 50-55 minutes until the top is a deep golden brown and a thin knife inserted into center of cake comes out clean. Place on a wire rack to cool for 20 minutes. Run a knife around edges. Invert cake and then turn right-side-up onto serving dish. Allow to cool for at least 1 hour before serving.