Preheat & Prep – Preheat the oven to 350°F and line a baking sheet with parchment paper.
Prepare the Mushrooms – Wipe the mushrooms with a damp cloth, remove the stems, and gently scrape out the gills. Brush each cap with olive oil and season with salt and pepper.
Cook the Beef – In a skillet over medium heat, brown the ground beef, breaking it apart with a spatula. Drain excess grease. Stir in 1 cup of marinara sauce and let it simmer for a few minutes.
Mix the Ricotta Filling – In a bowl, combine ¼ cup of mozzarella cheese, ricotta, parmesan, Italian seasoning, salt, and pepper.
Assemble the Mushrooms – Divide the ricotta mixture evenly among the mushroom caps, spreading it out. Top each with 3-4 tablespoons of the beef mixture, then sprinkle the remaining mozzarella cheese over the tops.
Bake to Perfection – Place the stuffed mushrooms on the baking sheet and bake for 20 minutes, or until the cheese is melted and bubbly and the mushrooms are tender.
Garnish & Serve – Sprinkle with chopped parsley and serve with the remaining marinara sauce for dipping.