Cafe Barbette Blueberry Pecan Sour Cream Coffee Cake

Topping
1/2 cup brown sugar
1 cup pecans
1 tablespoon cinnamon
1/2 cup cake flour
4 tablespoons ( 1/2 stick) unsalted butter, cold

Cake
2 1/2 cups all-purpose flour, plus extra for preparing pan
2 1/2 tablespoons baking powder
1/2 tablespoon baking soda
1/4 tablespoon salt
1 cup (2 sticks) unsalted butter at room temperature,
    plus extra for preparing pan
1 1/2 cups granulated sugar
3 large eggs
1 egg yolk
1 1/2 tablespoons vanilla extract
1 cup sour cream
Zest of 1 orange
1 1/2 cups blueberries, divided
1 tablespoon powdered sugar

To make topping: In the bowl of a food processor, pulse brown sugar, pecans, cinnamon and cake flour until combined. Add butter in small pieces and pulse until mixture resembles coarse meal. Divide in half and reserve.

To make cake: Preheat oven to 350°F. Butter and flour a 10-inch springform pan.

In a large bowl sift together flour, baking powder, baking soda and salt. Set aside.

In a large bowl using an electric mixer, cream butter and sugar until pale and fluffy. Add eggs one at a time, mixing well with each addition. Add yolk and mix well. Add vanilla extract, sour cream and zest, and mix until well-incorporated. Slowly add flour mixture, mixing well.

Divide batter in half. Spread half into prepared pan and top with 3/4 cup blueberries and half the topping mixture. Spread remaining batter into pan and top with the remaining blueberries and
topping mixture. Bake for 60 to 70 minutes, until a toothpick inserted into center of cake comes out clean. Let cool in pan on a rack for 5 to 10 minutes before unmolding. Dust with powdered sugar and serve warm.

Makes 8 servings.