Step 1: Preheat your oven to 375°F (190°C). Lightly grease a 9x13 inch baking dish.
Step 2: In a large bowl, whisk together the pumpkin puree, sweetened condensed milk, eggs, 1/2 cup brown sugar, cinnamon, ginger, nutmeg, cloves, and vanilla extract until smooth and well combined.
Step 3: Pour the pumpkin mixture evenly into the prepared baking dish.
Step 4: In a separate medium bowl, combine the flour, oats, granulated sugar, 1/2 cup brown sugar, and salt for the streusel topping.
Step 5: Add the cold, cubed butter to the dry streusel ingredients. Use a pastry blender, two knives, or your fingertips to cut the butter into the mixture until coarse crumbs form.
Step 6: Sprinkle the streusel topping evenly over the pumpkin filling in the baking dish.
Step 7: Bake for 45-55 minutes, or until the pumpkin filling is set and the streusel topping is golden brown and bubbly. A knife inserted near the center of the pumpkin filling should come out mostly clean.
Step 8: Let the crisp cool for at least 15-20 minutes before serving. It will firm up as it cools. Serve warm with your favorite toppings.