Fill large pot with enough water to cover pasta. Salt water generously and add dry pasta. Place pot on stovetop and cook according to package instructions, until pasta is just al dente (usually 1 to 2 minutes less than cook time on packaging).
Once pasta is cooked to al dente, scoop 1 cup of pasta water out of pot and set aside. Pour remaining pasta water and pasta through colander and drain pasta well. Return pasta to large pot and set aside.
Add ricotta, mozzarella, parmesan, garlic, Italian seasoning, lemon zest, and salt to large bowl. Use large spoon to stir ingredients together until combined.
Add ricotta mixture to large pot with penne pasta. Place pasta over medium-low heat and stir frequently until ricotta sauce is creamy and pasta is fully coated.
Add reserved pasta water in 1 tablespoon increments, stirring well between each addition, until sauce is thinned to desired consistency.
While pasta and ricotta sauce cook together, warm marinara in small saucepan over medium heat.
Once marinara is warmed through, and pasta and ricotta sauce are as desired, divide pasta evenly into serving bowls. Top each bowl with approximately ½ cup marinara sauce and serve warm.