Boil the pasta and broccoli. Bring a large pot of salted water to a boil. Cook 10 ounces of penne pasta until al dente, about 10-12 minutes. In the last 2 minutes, add 2 cups of broccoli florets. Drain and set aside.

Sauté the garlic. Heat 2 tablespoons of olive oil in a skillet over medium heat. Add 1 teaspoon of minced garlic and sauté for about 30 seconds.

Create the roux. Sprinkle 1 tablespoon of all-purpose flour over the garlic, whisk continually for about 1 minute. Gradually add 1 cup of vegetable broth and 1 cup of heavy cream, stirring to avoid lumps. Simmer for 4-5 minutes.

Incorporate the cheese. Remove from heat, add 1 cup of grated Parmesan cheese, stirring until melted. Season with salt, black pepper, and crushed red pepper if desired.

Combine pasta and sauce. Add drained pasta and broccoli to the sauce, toss gently. Stir in 2 tablespoons of fresh lemon juice and 2 tablespoons of chopped fresh basil.

Serve and garnish. Transfer to a serving dish, sprinkle with extra Parmesan and fresh basil if using. Serve immediately.