Creating these delightful Peach Crumble Bars is straightforward if you follow these easy steps:

1. Preheat Oven: Preheat your oven to 350°F (175°C) and grease a 9×13 inch baking dish.
2. Mix Dry Ingredients: In a large bowl, combine the flour, granulated sugar, baking powder, and salt.
3. Combine Wet Ingredients: In another bowl, mix the melted butter and egg until well combined.
4. Combine Mixtures: Add the wet mixture to the dry ingredients and stir until crumbly.
5. Press into Pan: Press about two-thirds of this mixture into the bottom of the prepared baking dish. This will serve as the crust.
6. Prepare Peaches: In a separate bowl, toss the sliced peaches with lemon juice, ground cinnamon, and a tablespoon of sugar.
7. Layer Peaches: Spread the peach mixture evenly over the crust in the baking dish.
8. Add Crumble Topping: Sprinkle the remaining crumble mixture over the peaches, followed by the rolled oats and brown sugar for added texture.
9. Bake: Place the dish in the preheated oven and bake for 35-40 minutes or until the topping is golden brown and the peaches are bubbly.
10. Cool: Remove from the oven and let cool in the pan for at least 30 minutes before cutting into bars.

By following these steps, you’ll have a delightful batch of Peach Crumble Bars that are sure to impress!