Prepare the pan: Heat the oven to 350°F and line a 9-inch square pan with parchment paper.
Make the crust: Mix graham cracker crumbs, melted butter, and sugar. Press firmly into the pan.
Prepare the filling: Beat softened cream cheese, eggs, sugar, vanilla, and salt until smooth.
Layer the peaches: Spread the cheesecake mixture over the crust and scatter the diced peaches evenly on top.
Make the crumble: Combine flour, brown sugar, cinnamon, and salt. Stir in melted butter until coarse crumbs form.
Bake: Sprinkle the crumble over the peaches and bake for 35 to 40 minutes, until the edges are set and the center gently wobbles.
Chill and slice: Cool completely, refrigerate for at least one hour, then lift from the pan and cut into bars.