Preheat oven to 375°F (190°C).
In a large oven-safe skillet over medium heat, add olive oil and sauté the garlic for 30 seconds, just until fragrant.
Stir in the uncooked orzo and pour in the broth. Bring to a gentle simmer
Reduce heat to medium-low and cook, stirring occasionally, for 8–10 minutes, until the orzo is al dente and most of the liquid is absorbed.
Remove the skillet from heat. Stir in ricotta cheese, cream, Parmesan, salt, black pepper, and red pepper flakes (if using) until smooth and creamy.
Fold in the spinach until evenly distributed.
Sprinkle mozzarella cheese evenly over the top.
Transfer the skillet to the oven and bake uncovered for 10–12 minutes, or until bubbly and lightly golden.
Remove from oven and let rest for 5 minutes before serving.