1. Position a rack in the center of the oven and heat the oven to 350 degrees F.

2. In a food processor, combine the flour, sugar, baking powder, and salt. Pulse briefly to blend the ingredients. Add the butter pieces and pulse until they are the size of small peas, 5 to 7 one-second pulses.

3. Dump the mixture into a large mixing bowl. Add the pecans and cinnamon and stir until evenly dispersed. Add the sour cream. Using a rubber spatula, gently smear the ingredients together until the flour is evenly moistened and the dough begins to form large, soft, moist clumps. Bring the dough together into an 8-inch-long log. Divide the log into 10 roughly equal round pieces. Refrigerate the pieces in the bowl while preparing the fruit.

Put the berries into a large bowl. Toss with the granulated sugar, flour, and salt. Add the ginger and vanilla and toss gently.

1. Pile the fruit into a 9x13-inch Pyrex (or similar) baking dish, scraping in any remaining juices or sugar from the bowl, and spread evenly. Remove the pieces of the dough from the refrigerator and arrange them randomly on top of the filling, leaving spaces between the pieces. Don't be tempted to flatten the dough--the large pieces are important for proper and even baking of the filling and topping. If desired, sprinkle a little granulated, turbinado, or demerara sugar evenly over the cobbler.

2. Bake until the filling is bubbling and the topping is browned, 50 to 60 minutes. Let sit about 20 minutes to allow the juices to settle. You can serve this cobbler hot or warm (it will stay warm at room temperature for 1 to 1-1/2 hours). Serve with lightly sweetened whipped cream or vanilla ice cream, if you like.

You can prepare the dough up to 8 hours ahead; simply cover the bowl with plastic wrap and store it in the refrigerator until you're ready to proceed with the recipe.