Add the whole peeled tomatoes and their juices to a blender. Blend until mostly smooth and set aside.

Heat the olive oil in a large Dutch oven over medium-low heat. Add the garlic and cook for 2–3 minutes, stirring frequently, until fragrant and softened. Be careful not to brown or burn the garlic.

Stir in the tomato paste and cook for another 2–3 minutes. Add the red pepper flakes and Italian seasoning, stirring for about 30 seconds.

Add the mixture to blender and blend everything. Pour it all back into the dutch oven and give a stir. Season with salt and black pepper. Bring to a gentle simmer, then reduce the heat to low. Simmer uncovered for 25–35 minutes, stirring occasionally, until the sauce has thickened slightly and the flavors have developed.

Meanwhile, cook the ravioli according to the package directions. Before draining, reserve about 1 cup of pasta water.

If you’d like a completely smooth sauce, carefully blend it until smooth. Return it to the Dutch oven over low heat. Stir in the heavy cream and Parmesan until combined.

Stir in the spinach, allowing the spinach to wilt into the sauce.

Add the cooked ravioli to the sauce and gently toss to coat. Add a splash of reserved pasta water as needed to loosen the sauce and help it cling to the ravioli.

Finish with additional freshly grated Parmesan and fresh basil, if desired.