Step 1: Preheat your oven to 350°F (175°C).
Step 2: In a large mixing bowl, combine the pumpkin puree, sweetened condensed milk, eggs, salt, and pumpkin pie spice. Whisk until smooth.
Step 3: Grease a 9x13-inch baking dish and pour the pumpkin filling into it, spreading evenly.
Step 4: In another bowl, mix the brown sugar, flour, salt, cinnamon, and pumpkin pie spice. Stir in the melted butter until crumbly.
Step 5: Sprinkle the topping evenly over the pumpkin filling.
Step 6: Bake for 40-45 minutes until the topping is golden brown and the filling is set.
Step 7: Allow to cool for 15 minutes before serving. Enjoy warm with whipped cream or ice cream!