Preheat an oven to 350°F and line a baking sheet with parchment paper. Place butternut squash on the baking sheet and toss with 3 tablespoons olive oil. Season well with kosher salt and black pepper. Bake squash until tender and just starting to turn golden in a few spots (35 – 40 minutes). Measure out 1 1/2 cups of cooked butternut squash and place in a small bowl. Add a pinch of crushed red pepper flakes, toss to combine, and set aside. Place remaining cooked butternut squash in food processor, and process until smooth. Add maple syrup and lemon juice, and pulse a few more times to combine. Season to taste with additional kosher salt.

Increase oven temperature to 500°F, and set an oven rack in the lowest possible position. Lightly spray a pizza pan or baking sheet with nonstick spray. Stretch pizza dough into a round large enough to fit the pizza pan. Very lightly drizzle the dough with olive oil, then use your hands to evenly spread the oil around. Sprinkle dough with a small pinch of kosher salt. Top pizza with grated mozzarella cheese and crumbled Gorgonzola. Using a spoon, drop large dollops of butternut squash puree around the pizza (you may not use all of the puree). Scatter cooked butternut squash cubes, red onion slices and chopped sage on top. Finish with a small sprinkle of kosher salt and black pepper.

Transfer the pizza pan to the oven on the lowest rack, and cook until the crust is golden brown (I check the bottom of the crust) and the cheese is nice and bubbly.