Light 25–30 charcoal briquettes in a chimney starter and allow to burn until fully gray and glowing, about 20–25 minutes. While coals heat, brown the Italian sausage in the Dutch oven directly over a campfire grate or camp stove over medium-high heat, breaking it apart as it cooks, about 7–8 minutes until no pink remains. Drain excess fat.

Add minced garlic, Italian seasoning, and red pepper flakes to the sausage and stir for 1 minute until fragrant. Pour in the marinara sauce and stir to combine. Add 1/4 cup water to thin slightly. Remove sausage mixture to a bowl or leave in pot and set aside.

In a bowl, combine whole-milk ricotta, egg, half the Parmesan, parsley, salt, and pepper. Stir well until smooth and fully combined. Set aside.

Lightly grease the inside of the clean 12-inch Dutch oven with olive oil or cooking spray. Spread a thin layer of the meat sauce (about 1/2 cup) on the bottom of the pot to prevent sticking.

Layer 1: Place a layer of no-boil lasagna noodles over the sauce, breaking and overlapping to cover as much surface as possible.

Layer 2: Spread half the ricotta mixture over the noodles. Top with one-third of the shredded mozzarella.

Layer 3: Ladle half the remaining meat sauce over the cheese layer.

Layer 4: Add another layer of no-boil noodles, then the remaining ricotta, another third of the mozzarella, and the remaining meat sauce.

Layer 5: Top with a final layer of noodles, then pour any remaining sauce over the top. Finish with the remaining mozzarella and sprinkle the rest of the Parmesan across the top.

Place the lid on the Dutch oven. Set up your coal arrangement: place 9 coals in a ring on the ground or a fireproof surface, then set the Dutch oven on top. Place remaining 16 coals on the lid, distributed evenly.

Cook for 45–55 minutes, rotating the Dutch oven a quarter turn and the lid a quarter turn in the opposite direction every 15 minutes for even heat distribution. Replace any spent coals as needed to maintain temperature.

The lasagna is done when the cheese is fully melted and bubbling, the top is golden with lightly browned spots, and a knife or skewer inserted into the center meets little resistance from the noodles. Internal temperature should read at least 165°F.

Remove the Dutch oven from the coals and let it rest with the lid on for 10 minutes before serving. This allows the layers to set for cleaner slices.

Use a spatula to slice and serve directly from the pot. Garnish with additional fresh parsley or Parmesan if desired.