Preheat the oven to 400 degrees F (200 degrees C).
Combine delicata squash and 2 tablespoons olive oil in a bowl and mix well. Spread out on a baking sheet and season with salt and pepper.
Bake in the preheated oven until delicata squash has softened, about 10 minutes. Cut into pieces.
Increase oven temperature to 450 degrees F (230 degrees C).
Divide pizza dough into 2 equal pieces. Dust a work surface with flour and roll dough out into 2 pizza rounds.
Dust 2 baking sheets with cornstarch and transfer pizza rounds onto baking sheets. Brush each pizza first with 1 tablespoon olive oil, followed by 2 tablespoons pesto. Sprinkle mozzarella cheese and Parmesan cheese on top. Sprinkle squash pieces on top of cheese.
Bake in the hot oven until pizza crust is crispy, about 10 minutes. Sprinkle with pecan nuts.
