Gladys Potter, Rick Bayless's grandmother, was acclaimed in the family for this dessert.
For the Pastry
- 2 2⁄3 cups flour
- 1 tsp. salt
- 1⁄4 tsp. baking powder
- 16 tbsp. cold unsalted butter, cut into pieces
- 6 oz. cold cream cheese, cut into pieces
- 1 tbsp. cider vinegar
- 2-3 tbsp. milk or half-and-half
- 2 tbsp. sugar
For the Filling
- 5 lb. ripe peaches, peeled, pitted, and cut into 1" pieces
- 1–1 1⁄4 cups sugar
- 5 tbsp. cornstarch
- 1 1⁄2 tbsp. fresh lemon or lime juice
- Heaping 1/2 tsp. freshly grated nutmeg
- 1⁄2 tsp. salt
- 2 tbsp. unsalted butter, cut into pieces
For the pastry: Put flour, salt, baking powder, butter, and cream cheese into a food processor and pulse until mixture resembles coarse meal, 6–10 pulses. Drizzle in vinegar and 3 tbsp. cold water and pulse until mixture begins to clump together (it won't form a ball), 6–10 pulses. Transfer to a large sheet of plastic wrap, press dough together, gather plastic wrap over dough, then flatten into a 10" square. Refrigerate dough for 1 hour.
For the filling: Combine peaches, sugar, cornstarch, lemon juice, nutmeg, and salt in a large bowl and set aside.
Preheat oven to 400°. Cut off two-thirds of the dough, roll out on a floured surface into a 14" x 18" rectangle, and ease into a 9"x 13" baking dish. Brush rim of dough with milk, fill pastry with peaches, and dot with butter. Roll remaining dough out on floured surface into a 10"x14" rectangle, cut lengthwise into 12 strips, and lay on top of filling in a lattice pattern. Crimp and trim edges. Brush strips with milk and spinkle with remaining sugar. Bake for 15 minutes , reduce heat to 350°, and bake until pastry is golden brown, 30-40 minutes more. Let cool briefly before serving.