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 prepared pan bottom.
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, and salt until completely smooth and incorporated.
05 - Pour pumpkin filling evenly over the warm crust. Spread gently with a spatula to create an even layer.
06 - Mix flour, brown sugar, cinnamon, salt, and melted butter until crumbly and well combined.
07 - Sprinkle streusel evenly over the pumpkin filling. Bake for 30 minutes until center is set and topping is golden brown.
08 - Cool completely in the pan. Using parchment overhang, lift bars from pan and cut into 16 squares.