Blueberry Buttermilk Crumb Cake

Nonstick cooking spray

Crumb Topping:

¾           cup unbleached, all-purpose flour

½           cup packed light brown sugar

8            tablespoons (1 stick) unsalted butter, cut into 1-inch pieces and at room temperature

1½         teaspoons ground cinnamon

½           teaspoon pure vanilla extract

Pinch kosher salt

Buttermilk Cake:

1⅓                  cups unbleached, all-purpose flour

½           teaspoon baking soda

¼           teaspoon cream of tartar

¼           teaspoon kosher salt

⅓                      cup (5 tablespoons + 1 teaspoon) unsalted butter, cut into 1-inch pieces and softened to room temperature

⅔                      cup granulated sugar

1            large egg, at room temperature

½           teaspoon pure vanilla extract

⅓                      cup buttermilk

1                cup fresh blueberries

Nutritional analysis per serving (based on 12 servings):  Calories 271 (42% from fat) • carb. 37g • pro. 3g fat 13g • sat. fat 9g • chol. 52mg • sod. 77mg calc. 10mg • fiber 1g

1. Preheat oven to 350°F. Lightly coat a 9-inch square baking pan with cooking spray; reserve.
2. Prepare the Crumb Topping: Put all of the crumb topping ingredients in the Cuisinart® mixing bowl. Attach the flat mixing paddle and mix on Speed 2 to break up, scrape if necessary and then increase to Speed 4, until the mixture resembles large crumbs. Remove and reserve in refrigerator until ready to use.
3. To prepare the Buttermilk Cake: Put the flour, baking soda, cream of tartar and salt in a medium bowl and stir to combine; reserve.
4. Put the butter and granulated sugar in the Cuisinart® mixing bowl. Attach the flat mixing paddle and mix on Speed 3 until incorporated. Scrape the entire bowl, increase to Speed 5 and mix until light and fluffy, about 1 minute.
5. Scrape the bowl well and reduce speed to 3. Add the egg and the vanilla extract and mix until fully incorporated and batter is smooth. Scrape the entire bowl.
6. Add half the reserved dry mixture and half the buttermilk. Mix on Speed 2 until just blended. Scrape the entire bowl. Add remaining dry ingredients and buttermilk. Continue mixing on Speed 2 until smooth and blended.
7. Pour batter into prepared pan and smooth over top. Sprinkle blueberries evenly over the top; lightly press blueberries into batter (submerge blueberries slightly). Crumble any large clumps in the crumb mixture and sprinkle the crumb mixture evenly over the blueberries.
8. Bake in preheated oven until crumbs are evenly golden brown and tester is clean when inserted in center of pan, about 30 to 35 minutes. Remove from oven and cool on a wire rack before cutting.