Boil a large pot of salted water. Add the tortellini and cook according to package instructions until al dente. Drain and set aside.
In a large skillet, heat the olive oil over medium heat. Add the minced garlic and sauté for about 1 minute, until fragrant.
Pour in the diced tomatoes, including their juice, and stir. Cook for about 3-4 minutes.
Reduce the heat to low, then add the heavy cream to the skillet, stirring to combine.
Stir in the cooked tortellini, chopped spinach, Italian seasoning, salt, and pepper. Cook for another 3-5 minutes, or until the spinach wilts and the sauce thickens slightly.
Remove from heat and stir in the grated Parmesan cheese until melted and creamy.
Serve immediately, garnished with fresh basil leaves.
Notes
Serve immediately for the best flavor and texture.