1. Place the peach slices in a medium bowl. Add the lemon juice, cornstarch, 1/4 cup of sugar and cinnamon. Gently toss to coat. Set aside.

2. Preheat the oven to 375 degrees. Lightly mist an 8×8 inch pan with cooking spray or line with parchment. Set aside.

3. In a clean medium mixing bowl, whisk together the flour, remaining 1/2 cup sugar, baking powder, salt, lemon zest, and egg.

4. Cut in the butter using a pastry cutter, or two knives, until the butter resembles coarse crumbs (peas sized).

5. Pour half of the crumble mixture into the prepared 8 inch pan. Use the bottom of a measuring cup to firmly press into the bottom of the pan.

6. Using a slotted spoon, scoop the peaches and spread evenly over the mixture, trying to leave off any juices that may have formed in the bowl.

7. Sprinkle the remaining crumb mixture over the top of the peach layer.

8. Bake 40 to 45 minutes, or until just lightly browned. Serve immediately or keep stored in an air tight container.