Duo Challenge Day Coffee Cake

Blueberry Crumble Coffee Cake

This past weekend, I made this coffee cake for a potluck picnic and bbq. I knew I wanted to make something with fruit because it's summer. Originally, I was thinking about grilling pineapple, but finally settled on a blueberry coffee cake because the last coffee cake I made came out so yummy. This blueberry version came out delicious as well...moist and chock full of blueberries. There was almost a 1-1 ratio of blueberries to batter.

Here is my adaptation of the recipe. I used 1.5 the recipe so I could make a 9x13 cake.

Blueberry Crumble Coffee Cake

adapted from Cook's Illustrated

Ingredients:
Streusel
3/4 cup all-purpose flour
1/2 cup packed brown sugar
3 tbs granulated sugar
1/2 tsp ground cinnamon
 pinch table salt
6 tbs unsalted butter, cut into pieces, softened

Cake
2 1/4 cups all-purpose flour
2 1/4 tss baking powder
15 tbs unsalted butter, softened
1 cup granulated sugar
3/4 tsp salt
1/2 teaspoon grated lemon zest
2 1/4 teaspoons vanilla extract
3 large eggs , room temperature
6 cups fresh blueberries, washed

Directions:

1. In a medium-sized bowl, whisk together flour, sugars, cinnamon, and salt until well combined. Add butter and mix with hands (squeeze pieces of butter so they break apart) until mixture resembles wet sand and no large butter pieces remain. Set aside.
2. For the cake: Adjust oven rack to lower-middle position; heat oven to 350 degrees. Spray a 9x13 pan with 2-inch sides with nonstick cooking spray, line bottom with parchment, and spray again with nonstick cooking spray. 
3. Whisk flour and baking powder in small bowl to combine; set aside. 
4. In standing mixer fitted with a paddle, cream butter, sugar, salt, and lemon zest at medium-high speed until light and fluffy, about 3 minutes; using a rubber spatula, scrape down bowl. 
5. With mixer running at medium speed, add eggs one at a time; beat until combined, scraping the bowl as necessary. Beat in vanilla until combined, about 30 seconds. 
6. With mixer running on low speed, gradually add flour mixture; beat until flour is combined, but don't over mix. Using a spatula, gently fold in blueberries until evenly distributed.
7. Transfer batter to prepared pan; with rubber spatula spread batter evenly to pan edges and smooth surface. Sprinkle streusel over the batter by squeezing handfuls to form a clump and then breaking the clump and distributing evenly.
8. Bake until deep golden brown and toothpick or wooden skewer inserted into center of cake comes out clean, about 45-50 minutes. Cool on wire rack 15 to 20 minutes. Cut into squares and serve.