Firstly, In a large mixing bowl add the flour, granulated sugar, diced butter, and water.
Start rubbing the butter into the flour mixture and form a smooth dough.
Take ⅔ of the dough and press it down in an 8x8 inch brownie pan lined with parchment paper and smooth it out.
In another bowl toss the diced peaches with the sugar, cornstarch, vanilla extract, and cinnamon together and transfer the mixture on top of the crust in the pan.
Take the rest of the dough and crumble it on top of the peaches.
Bake the peach pie bars in an already heated oven at 350 F or 180 C degrees for about 30 minutes.
In conclusion, Let the peach pie bars cool slightly and cut them into 9 equal pieces.