1/2 cup butter, softened 1 cup sugar, divided 1 large egg 1 teaspoon grated orange zest 1-1/2 cups plus 1 tablespoon all-purpose flour, divided 1/2 teaspoon baking soda 1/8 teaspoon salt 1/2 cup sour cream or plain yogurt 2 cups fresh blackberries Confectioners’ sugar, optional
Preheat oven to 350°. Grease and flour a 9-in. springform pan.
In a large bowl, cream butter and 3/4 cup sugar until light and fluffy. Beat in egg and orange zest. In another bowl, whisk 1-1/2 cups flour, baking soda and salt; add to creamed mixture alternately with sour cream, beating well after each addition. Transfer to prepared pan.
In a bowl, toss blackberries with remaining flour; arrange over batter. Sprinkle with remaining sugar. Bake 40-45 minutes or until a toothpick inserted in center of cake portion comes out clean.
Loosen sides from pan with a knife; remove rim from pan. Cool on a wire rack; serve warm or at room temperature. If desired, dust with confectioners’ sugar before serving.