In a large skillet over medium-high heat, add the broth, pesto, heavy cream, and lemon juice; stir until the pesto is incorporated and the mixture begins to bubble.
Add the refrigerated ravioli to the bubbling sauce and stir to coat evenly.
Cover the skillet and reduce heat to medium-low; cook 5 minutes with the lid on to allow the ravioli to cook and the sauce to thicken.
Uncover and stir the ravioli; if the sauce is still too thin, cook uncovered a few more minutes until it reaches the desired thickness.
Stir in the packed baby spinach, cover briefly, and cook 1–2 minutes until the spinach wilts.
Season with salt and pepper to taste and sprinkle with grated Parmesan, if desired; serve immediately.
