Bring a large pot of lightly salted water to a boil. Add penne and cook following package directions, 11 minutes. Add zucchini and peas during last 3 minutes. Stir in spinach. Drain and place back into the pot.
Meanwhile, heat oil in a large nonstick skillet over medium-high heat. Add onion and cook 5 minutes, stirring occasionally; add Canadian bacon and vodka and cook 1 minute. Stir in tomatoes, tomato sauce, salt and red pepper. Reduce heat to medium-low and simmer, uncovered, for 10 minutes.
Stir half-and-half and 1/4 cup cheese into the sauce. Toss with pasta and let stand for 10 minutes. Stir and spoon into serving bowl and top with remaining cheese.