01 -
Preheat your oven to 375°F (190°C) and grease a 9x13-inch baking dish.
02 -
In a bowl, mix the flour, granulated sugar, baking powder, and salt. Add the cold butter and egg, blending with your hands or a pastry cutter until the mixture forms coarse crumbs. Press half of this mixture into the prepared baking dish to form the base.
03 -
In a separate bowl, toss the peach slices with lemon juice, brown sugar, cinnamon, nutmeg, and cornstarch until evenly coated.
04 -
Spread the seasoned peach mixture over the base layer, then sprinkle the remaining crumb mixture on top to cover the peaches.
05 -
Bake for 40 to 45 minutes, until the top is golden brown and the peach layer is bubbly. Let the bars cool completely before cutting them into squares.