This beautiful dessert combines two delicious summer fruits—plums and raspberries. For a rich finishing touch, top each serving with a dollop of sweetened crème fraîche.
For the filling:
3 1/2 lb. (1.75 kg) plums, pitted and each cut into 6 wedges
1/2 cup (4 oz./125 g) sugar
3 Tbs. cornstarch
1 Tbs. vanilla extract
2 3/4 cups (11 oz./345 g) raspberries
For the topping:
3/4 cup (6 fl. oz./180 ml) buttermilk
1 tsp. vanilla extract
1 1/2 cups (7 1/2 oz./235 g) all-purpose flour
1/2 cup (2 1/2 oz./75 g) medium-grind cornmeal
1/4 cup (2 oz./60 g) plus 1 Tbs. sugar
1 Tbs. baking powder
1/2 tsp. salt
1 Tbs. lemon zest
6 Tbs. (3/4 stick) (3 oz./90 g) cold unsalted butter, cut into 6 pieces
Preheat an oven to 400°F (200°C). Butter a 14-by-10-inch (35-by-25-cm) baking dish.
To prepare the filling, in a large bowl, toss together the plums, sugar, cornstarch and vanilla. Stir in the raspberries. Spread the filling in the prepared dish. Transfer to the oven and bake for 15 minutes.
Meanwhile, prepare the topping: In a medium bowl, whisk together the buttermilk, egg and vanilla. In another bowl, whisk together the flour, cornmeal, the 1/4 cup (2 oz./60 g) sugar, the baking powder, salt and lemon zest. Using a pastry blender, cut in the butter until crumbly. Add the buttermilk mixture and stir just until a dough forms.
Remove the filling from the oven. Reduce the oven temperature to 375°F (190°C).
Drop the dough onto the filling in 9 evenly spaced mounds. Sprinkle the dough with the 1 Tbs. sugar. Transfer to the oven and bake until the fruit is bubbling and a toothpick inserted into the topping comes out clean, about 30 minutes.
Transfer the baking dish to a wire rack and let the cobbler cool for 30 minutes before serving. Serves 8.