Creating Peach Crumb Bars is an enjoyable process that yields delicious results. Follow these steps for success:

1. Preheat the Oven: Preheat your oven to 350°F (175°C) and grease a 9×9-inch baking pan or line it with parchment paper.
2. Prepare the Crust: In a mixing bowl, combine the flour, sugar, baking powder, and salt. Add the softened butter and vanilla extract. Mix until crumbly.
3. Add the Egg: Incorporate the egg into the mixture, stirring until it forms a dough.
4. Press into Pan: Reserve about 1 cup of the crumb mixture for the topping. Press the remaining mixture evenly into the bottom of the prepared baking pan to create the crust.
5. Prepare the Peach Filling: In a separate bowl, combine the sliced peaches, lemon juice, cornstarch, and cinnamon. Gently toss until the peaches are well coated.
6. Spread the Filling: Pour the peach mixture over the crust in the baking pan, spreading it evenly.
7. Add the Topping: Crumble the reserved crumb mixture over the peach filling, covering it generously.
8. Bake: Place the pan in the preheated oven and bake for 35-40 minutes or until the topping is golden brown and the peaches are bubbling.
9. Cool: Remove from the oven and allow the bars to cool in the pan for about 30 minutes before slicing.
10. Slice and Serve: Cut into squares and serve warm or at room temperature.