Creating Heavenly Summer Peach Bars is a delightful journey. Follow these steps for a perfect outcome:

1. Preheat Your Oven: Begin by preheating your oven to 350°F (175°C). Prepare a 9×13 inch baking dish by greasing it or lining it with parchment paper for easy removal.

2. Make the Dough: In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy. This should take about 2-3 minutes.

3. Add Wet Ingredients: Beat in the egg and vanilla extract until fully incorporated.

4. Combine Dry Ingredients: In another bowl, whisk together the flour, baking powder, and salt. Gradually add it to the butter mixture, mixing until just combined. Do not overmix.

5. Spread the Crust: Scoop the dough into the prepared baking dish and press it evenly into the bottom to form the crust. It may seem thick, but it will spread as it bakes.

6. Prepare the Peach Filling: In a separate bowl, toss the sliced peaches with lemon juice, cornstarch, cinnamon, and nutmeg (if using). Ensure the peaches are evenly coated.

7. Layer the Filling: Pour the peach mixture over the pre-baked crust, spreading it evenly.

8. Sprinkle Sugar: If desired, add a light sprinkle of sugar over the peach filling for added sweetness.

9. Bake: Place the baking dish in your preheated oven and bake for 40-45 minutes, or until the edges are golden brown and the filling is bubbly.

10. Cool: Once baked, remove from the oven and allow the bars to cool in the pan for at least 30 minutes. This will help them set before slicing.

11. Slice and Serve: Once cooled, cut the bars into squares and serve them warm or at room temperature.

These straightforward instructions will guide you to creating Heavenly Summer Peach Bars effortlessly, ensuring you achieve delicious results every time!