Creating Heavenly Summer Peach Bars is easy if you follow these steps carefully:

1. Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking dish or line it with parchment paper for easy removal.
2. Make the Crust: In a medium bowl, combine softened butter, granulated sugar, and egg. Mix until creamy.
3. Add Dry Ingredients: Stir in flour, baking powder, and salt. Mix until the dough begins to come together.
4. Press Dough: Reserve a cup of dough for topping. Press the remainder evenly into the bottom of the prepared baking dish to form a crust.
5. Prepare Peaches: In a small bowl, combine sliced peaches with lemon juice and ground cinnamon if using. Toss gently to coat.
6. Layer Peaches: Spread the peach mixture evenly over the crust in the baking dish.
7. Add Topping: Crumble the reserved dough over the peach layer evenly.
8. Bake: Place the dish in the preheated oven. Bake for 35-40 minutes or until the topping is golden brown and the peaches are bubbly.
9. Cool: Allow the bars to cool in the pan for at least 20-30 minutes.
10. Slice and Serve: Once cool, slice into bars and dust with powdered sugar if desired.

By following these steps, you will effortlessly create an incredible dessert that embodies the flavors of summer.