For the crust & crumb: – 2½ cups all-purpose flour – 1 cup granulated sugar – ½ teaspoon baking powder – ¼ teaspoon salt – 1 cup unsalted butter (cold, cubed) – 1 large egg For the filling: – 4 cups fresh or frozen sliced peaches – ⅓ cup granulated sugar – 2 teaspoons cornstarch – 1 tablespoon lemon juice – ½ teaspoon ground cinnamon
Combine flour, sugar, baking powder, and salt. Cut in cold butter, then mix in egg until crumbly dough forms.
Press two-thirds of the crumb mixture into a greased 9x13-inch pan to form a firm, even crust. Set aside remaining dough.
Toss sliced peaches with sugar, cornstarch, lemon juice, and cinnamon. Let sit 5–10 minutes to draw out the juices.
Spread peach mixture evenly over the prepared crust. Use a slotted spoon if too juicy to avoid sogginess.
Sprinkle remaining crumb dough over the peach layer. Leave some gaps so the filling can bubble through when baked.
Bake at 375°F (190°C) for 40–45 minutes, or until the top is golden and the peach filling is bubbling at the edges.