In a large bowl whisk together the flour, 1 cup granulated sugar, baking powder, salt, and ¼ tsp. cinnamon.
Cut in the butter with a pastry blender until butter is mixed in and coarse crumbs have formed.
Stir the vanilla and beaten egg together.
Add into the flour and butter mixture and combine.
Mixture will be crumbly.
Pat half of the crust ingredients into the prepared baking dish.
Spread the peach mixture evenly over the bottom crust.
Crumble the remaining crust ingredients over the peach layer as a streusel topping.
Combine ¼ cup granulated sugar and 1 tsp. cinnamon.
Sprinkle cinnamon-sugar mixture over top of streusel topping.
Bake at 375° for 45-60 minutes, or until the top is golden brown and peach juice starts to bubble up around the edges.
Cool completely before cutting into bars.