Bring a large pot of salted water to a boil and cook the penne pasta according to package instructions until al dente, about 9 minutes.
Reserve 1/2 cup of the pasta cooking water and then drain the pasta.
In a large skillet, heat olive oil over medium heat.
Add minced garlic and sauté for 1 minute until fragrant.
Add chopped sun-dried tomatoes and cook for 2 minutes, stirring occasionally.
Add fresh baby spinach and cook until wilted, about 2 minutes.
Pour in the heavy cream and stir to combine.
Add grated Parmesan cheese, dried Italian seasoning, crushed red pepper flakes, salt, and black pepper. Stir until the cheese melts and the sauce thickens slightly.
Add the cooked pasta to the skillet and toss to coat evenly with the sauce.
If the sauce is too thick, add reserved pasta cooking water a little at a time until desired consistency is reached.
Remove from heat and stir in chopped fresh basil.
Allow the pasta to cool completely before transferring to a freezer-safe container.
Seal the container tightly and freeze for up to 3 months.
To reheat, thaw overnight in the refrigerator and warm in a skillet over medium heat, adding a splash of water or cream if needed.