Cook gnocchi in boiling water according to package directions.
While gnocchi cooks, heat oil in a large skillet over medium heat. Add squash; sauté 4 minutes or until crisp-tender. Add garlic; sauté 1 minute. Add spinach; cover and cook 2 minutes or just until spinach wilts. Reduce heat to low; stir in milk, pepper, and salt. Add gnocchi and cheese; stir gently. Serve immediately.