Bring a large pot of salted water to a boil. In a small bowl, whisk together ricotta, lemon juice, Parmesan, parsley, olive oil, lemon zest, salt and pepper. Set aside.
Add penne to boiling water and cook for 7 minutes or until tender. Add asparagus to pot for final 3 minutes of cooking time. Set aside 1 cup pasta water, then drain pasta mixture and place in serving bowl.
Add ricotta mixture and bacon to serving bowl and stir well to combine, adding reserved pasta water by the 1/4 cupful if necessary. Serve immediately.
