Preheat oven to 350°F if using a glass pan or dark metal pan, or 375°F for a light metal pan. Lightly grease or spray a 13x9-inch baking pan and set aside.

For the crust:

In a medium bowl whisk together 1 cup of sugar, 3 cups flour, baking powder, salt and cinnamon. Using a pastry cutter, blend in the butter until the mixture resembles coarse sand. Add the lightly beaten egg and mix until the dough starts to hold together, but is still crumbly. Gently press a little more than half the dough into the prepared pan.

OPTIONAL: you can also process the sugar, flour, baking powder, salt and cinnamon in the bowl of a food processor. Add the butter and process until the mixture resembles coarse sand. Add the egg and pulse until the dough starts to hold together.

For the peach mixture:

In a large mixing bowl whisk together the sugar, cornstarch and cinnamon. Add the diced peaches and toss to combine. Drizzle the lemon juice over the peaches and toss to coat. Pour the peach mixture over the crust and spread evenly.

Using your hands, press together handfuls of the remaining crumb topping to create clumps. Scatter the clumps and remaining crumbled topping over the fruit layer leaving some peaches showing through.

If using a glass pan, bake at 350°F degrees for 50-55 minutes or until lightly browned. If using a metal pan, bake at 375°F degrees for 40-45 minutes. Cool completely then chill before cutting and icing.

To prepare the icing:

Whisk together the powdered sugar, almond extract and milk. Drizzle on the bars just before serving.