Adapted from Cook’s Illustrated Magazine, July 2004
For the filling:
3 # ripe but firm peaches (about 8-9 medium), peeled, pitted and sliced
1/4 cup sugar
1 tsp cornstarch
1 Tbl fresh lemon juice (from about half a lemon)
pinch of kosher salt
For the topping:
1 cup all-purpose flour
1/4 cup plus 1 Tbl granulated sugar
3/4 tsp baking powder
1/4 tsp baking soda
1/2 tsp kosher salt
5 Tbl cold, unsalted butter, cut into 1/4-inch pieces
1/3 cup heavy cream
Preheat the oven to 350°F and position a rack in the lower third of the oven. Generously butter a 9x13-inch casserole dish.
For the filling: Toss the sliced peaches with the 1/4 cup sugar and let stand 30 minutes, stirring occasionally. Drain peaches in colander set over large bowl. Whisk together the peach juice, cornstarch, lemon juice, and salt in small bowl. Toss peach juice mixture with peach slices and transfer to prepared baking dish. Bake until peaches begin to bubble around edges, about 10 minutes.
For the topping: While peaches are baking, Combine the flour, 1/4 cup sugar, baking powder, baking soda, and salt in a large mixing bowl. Whisk to combine thoroughly. Scatter the cubed butter over the flour mixture. Using a pastry cutter, cut the butter into the dry ingredients, working until the mixture resembles coarse breadcrumbs. Add the cream and toss with a rubber spatula until until the dough just combines. Try not to over-mix, or the topping will be tough.
Break the dough into 6 evenly sized but roughly shaped mounds and set aside.
Remove the peaches from oven. Break the dough into 8 evenly sized but roughly shaped mounds, then place on top of the peach filling, spacing them at about 1/2-inch apart but not touching. Sprinkle each mound with a pinch of the remaining 1 Tbl sugar. Bake until topping is golden brown and fruit is bubbling, 16 -18 minutes. Cool on wire rack until warm, about 20 minutes. Serve, with each portion topped with vanilla ice cream.