Black-and-Blue Cobbler with Brown Sugar-Pecan Biscuits
Preheat oven to 375 degrees F. For biscuits, place pecans in a food processor. Cover and pulse with several on/off turns until roughly chopped. Add flour, brown sugar, baking powder, baking soda, and the 1/2 teaspoon salt. Cover and pulse with several on/off turns until combined. Add butter. Cover and pulse with several on/off turns until the biggest butter pieces are no larger than small peas.
Transfer flour mixture to a large bowl. Add buttermilk, stirring with a fork until the dough comes together. Transfer dough to a lightly floured surface; knead two or three times to bring dough together. Press dough into a rectangle or circle about 1/2 inch thick. Using a knife or a 2-1/2-inch fluted round cutter, cut out eight dough squares or rounds, rerolling scraps as needed.
In a 3-quart rectangular baking dish combine blackberries and blueberries. In a small bowl combine the 3/4 cup granulated sugar and the 1/4 teaspoon salt. Using the back of a spoon, press the lemon peel and ginger into the sugar mixture until it becomes fragrant. Pour the sugar mixture over the berries; gently toss with your hands to combine. In another small bowl stir together lemon juice and cornstarch. Add cornstarch mixture to berry mixture; gently toss together.
Brush tops of the biscuits with whipping cream; sprinkle with the coarse sugar. Arrange biscuits on top of the fruit. Bake for 25 minutes. Loosely cover the baking dish with foil; bake for 10 to 20 minutes more or until bubbly around the edges. Transfer baking dish to a wire rack; remove foil. Cool on rack for at least 20 minutes before serving.
To serve, divide fruit mixture among eight serving bowls; place a biscuit on each serving. Top with whipped cream.
Sweetened Whipped Cream
In a chilled mixing bowl combine whipping cream, sugar, and vanilla. Beat with an electric mixer on medium speed until soft peaks form (tips curl).