Step 1

Preheat the oven to 375 degrees F. Line a rimmed baking sheet with foil. Rub the butternut squash halves with the oil and place cut side down on the baking sheet. Roast 35-45 minutes or until fork tender.

Step 2

When cool enough to handle, scoop out the butternut squash flesh and purée in a food processor until smooth. You'll end up with roughly 4 - 4 1/2 cups of purée.

Step 3

Transfer the purée to a fine mesh sieve lined with cheesecloth placed over a bowl. Cover loosely with plastic wrap and let stand in the refrigerator overnight to allow liquid to drain from the purée.

Step 4

Preheat the oven 350 degrees F when you're ready to bake the casserole, and spray an 8x8" baking dish with cooking spray.

Step 5

Beat the butternut squash, eggs, maple syrup, milk, butter, cinnamon, vanilla and salt until smooth, then pour into the prepared baking dish.

Step 6

Combine the oats, flour, brown sugar, pecans, cinnamon, cardamom, and pinch of salt in medium bowl.

Step 7

Cut in the cold butter in with a pastry blender, fork, or your fingers, until it's in pea-sized clumps.

Step 8

Sprinkle the streusel evenly over the top of the butternut squash filling and bake at 350 degrees F for 45 minutes or until the streusel has browned and puffed up in the center.

Step 9

Cool on a wire rack for about 10 minutes, then serve.