Rhubarb Raspberry Cobbler With Cornmeal Biscuits

From The New York Times.
Ingredients:
Filling:
2 pounds rhubarb, trimmed and cut into 1/4-inch pieces (about 6 cups)
2 1/2 cups fresh raspberries or 1 (10-ounce) package frozen raspberries, defrosted
1 cup plus 2 tablespoons sugar
2 1/2 tablespoons cornstarch
Biscuits:
1 cup all-purpose flour, more as necessary
2/3 cup fine cornmeal
1/4 cup sugar
1 1/2 tablespoons baking powder
1/4 teaspoon kosher salt
6 tablespoons cold unsalted butter, cut into 1/2-inch cubes
2/3 cup heavy cream, more for brushing

1. Preheat oven to 350 degrees. For filling, in a large bowl, toss together rhubarb, raspberries, sugar and cornstarch. Allow mixture to stand while preparing biscuit dough.
2. To prepare biscuits, place flour, cornmeal, sugar, baking powder and salt in a food processor and pulse to combine (or whisk everything together in a bowl).
3. Add butter and pulse until mixture resembles coarse meal (or use 2 knives to cut butter into flour mixture). Pour in cream and continue pulsing (or stir) until dough starts to come together, scraping down sides of bowl if necessary.
4. Turn dough onto a lightly floured surface and gently pat it together. Divide it equally into 8 balls, then flatten them slightly into thick rounds. Biscuit dough can be made up to a day in advance and refrigerated, covered, until needed.
5. Scrape filling and accumulated juices into a 2 1/2-quart gratin or baking dish (9 by 12 inches). Arrange biscuits on top of filling and brush with cream. Bake for 40 to 45 minutes, or until filling is bubbling and biscuits are golden.
Yield: 8 servings.