01 - Preheat oven to 350°F. Line an 8x8-inch baking pan with parchment paper, allowing overhang for easy removal.
02 - Combine flour, brown sugar, and salt in a bowl. Cut in cold butter using a pastry blender or fork until mixture resembles coarse crumbs. Press firmly and evenly into the bottom of the prepared pan.
03 - Bake crust for 10 minutes until lightly set. Remove from oven and set aside.
04 - Whisk together pumpkin puree, maple syrup, brown sugar, eggs, pumpkin pie spice, vanilla extract, and salt until completely smooth and well combined.
05 - Pour pumpkin filling evenly over the warm pre-baked crust. Gently spread with a spatula to create a uniform layer.
06 - Mix flour, brown sugar, cinnamon, salt, and melted butter in a small bowl until crumbly. Sprinkle mixture evenly over the pumpkin filling.
07 - Bake for 30 minutes until the center is set and the streusel topping is golden brown. The bars should not jiggle in the center.
08 - Cool completely in the pan on a wire rack, approximately 2 hours. Use parchment overhang to lift bars from the pan, then cut into 16 equal squares.