Bring a large pot of salted water to a boil and cook the penne until al dente according to package directions; drain, toss with a drizzle of olive oil, and set aside.
In a large heavy-bottomed skillet over medium-high heat, melt 2 tablespoons butter with 1 tablespoon olive oil. Add the shrimp, season with 1/4 teaspoon salt and 1/4 teaspoon pepper, and cook about 2–3 minutes per side until opaque; transfer shrimp to a plate and remove tails if desired once cool enough to handle.
Do not wipe out the skillet. Add the remaining 1 tablespoon olive oil and heat over medium-high. Add the diced onion and sauté about 3 minutes until softened.
Add the chopped bell peppers and sauté 2 minutes, then add the sliced zucchini, minced garlic, and red pepper flakes and cook 1 more minute.
Stir in the crushed tomatoes, fire-roasted diced tomatoes (with their juices), tomato paste, sugar, chicken bouillon, oregano, parsley, thyme, and the additional 1/2 teaspoon salt and 1/2 teaspoon pepper. Bring to a gentle simmer and cook 8–10 minutes, stirring occasionally.
Reduce the heat, stir in the heavy cream and chopped basil, and warm through.
Add the cooked shrimp and drained pasta to the sauce, toss to combine and heat through; taste and adjust seasoning with salt, pepper, red pepper flakes, or sugar as desired.
Serve immediately and optionally garnish with grated Parmesan and parsley.