Put squash halves, cut sides down, in a microwave-safe dish. Add water and cover. Microwave on High until tender, about 12 minutes.

Meanwhile, heat oil in a large skillet over medium-high heat. Add sausage and cook until lightly browned, about 5 minutes. Transfer to a plate.

Cook onion and bell pepper in the same skillet until just tender, 6 to 8 minutes.

Stir vodka sauce and broccoli into skillet. Bring to a simmer and cook, covered, until broccoli is crisp-tender, 3 to 4 minutes.

Return sausage to skillet; stir to combine.

Carefully remove squash halves from dish. Using a fork, scrape squash strands into a serving dish.