Preheat your oven to 350°F (175°C) and grease a 9x13 inch baking dish.

In a mixing bowl, combine flour, sugar, cinnamon, and salt. Cut in the butter until resembling coarse crumbs. Mix in the egg until just combined.

Press the dough into the greased baking dish, compacting it to ensure even layers. Bake for about 10 minutes until slightly golden.

While the crust is baking, slice the peaches and toss them with sugar and cinnamon until well coated.

Remove the crust from the oven and spread the peach filling evenly over it.

Return to the oven and bake for 25 to 30 minutes until bubbly and golden brown. A toothpick should come out mostly clean.

Allow the bars to cool in the pan before slicing into squares to serve.