Blackberry Cobbler

I made this twice recently with freshly-picked local berries. Serve with vanilla ice cream.

Filling

1/2 cup sugar

2 tsp. cornstarch

2 tsp. arrowroot

2 tsp. tapioca flour

pinch ground cinnamon

pinch salt

8 cups fresh blackberries

1 1/2 tsp. grated lemon zest plus 1 Tbs. lemon juice

Topping

1 cup unbleached all-purpose flour

2 Tbs. stone-ground cornmeal (or polenta)

1/4 cup sugar

2 tsp. baking powder

1/4 tsp. baking soda

1/4 tsp. salt

4Tbs. (1/2 stick) unsalted butter, melted

1/3 cup buttermilk (or milk with lemon added)

1/2 tsp. vanilla extract

1/8 tsp. ground cinnamon

2 Tbs. coarse or raw sugar

Instructions

Adjust oven rack to lower-middle position and heat oven to 375 degrees. Butter the insides of a large ceramic casserole dish.

For the filling: Stir the sugar, cornstarch, arrowroot, tapioca, cinnamon, and salt together in a small bowl (use about 2 Tbs. of any combination of thickeners). Rinse the berries (I soak them in water and drain several times) and shake gently to dry. Place the berries in the casserole dish, sprinkle on the sugar mixture, lemon zest and juice and mix gently. Bake until the filling is hot and bubbling around the edges, about 25 minutes.

For the topping: Whisk the flour, cornmeal, sugar, baking powder, baking soda, and salt to combine. In a separate large bowl whisk the buttermilk and vanilla. Just before the berries come out of the oven, add the dry ingredients to the buttermilk mixture and stir gently with rubber spatula. Add the melted butter and mix until thoroughly combined.

Remove the berries from the oven; increase oven temperature to 425 degrees. Pinch off walnut-sized pieces of dough, flatten them (about 1/4 inch thick), and place on the hot berry filling, spacing the chunks at least 1/2 inch apart. Sprinkle the dough with raw sugar. Bake until the filling is bubbling and the biscuits are golden brown on top and cooked through, 15 to 18 minutes. Cool the cobbler on a wire rack 20 minutes and serve.

[adapted from Baking Illustrated]