Preheat your oven to 350 degrees Fahrenheit.

Make the base: Get out a large bowl and add the 1 cup of flour, ¼ cup of sugar, and ¼ teaspoon of salt into it. Use a spoon to mix these three ingredients together. Then add the cubes of butter, and use either a pastry blender or two knives to incorporate the butter into the mixture until it forms pea-sized pieces.

Bake the base: Get out an 8×8 inch baking pan and line it with either some aluminum foil that overhangs the sides of the pan. Then grease the aluminum with either a stick of butter or some pam. Then pour the base mixture into the pan and use your hands to firmly press it into the bottom of the pan. Stick this in your oven and let it bake for 10 minutes.

Prepare the peach filling by adding the ingredients to a bowl, and mixing them together.

Prepare the streusel topping by adding the flour, sugar, pecans, and oats to a bowl. Then add in the butter, and work it in with your hands until it forms coarse crumbs.

Finish the peach crumble bars: After the base has baked for 10 minutes, take it out of the oven. Then carefully spoon the peach filling evenly over the base. Follow this up with the streusel topping. Then add this back to your oven and bake for 30 to 35 minutes until the peaches are bubbling, and the streusel topping has become golden brown.

Let the peach crumble bars cool completely before you cut them up into bars. Enjoy!