Heat the oven: Preheat to 375°F (190°C). Line a 9x13-inch baking sheet or jelly roll pan with parchment.
Make the keto “noodle” batter: In a bowl, beat cream cheese until smooth.
Whisk in eggs one at a time. Stir in mozzarella, Parmesan, Italian seasoning, garlic powder, onion powder, and salt until combined.
Bake the noodle sheet: Spread the mixture evenly on the lined pan. Bake 15–18 minutes until set and lightly golden around the edges.
Cool, then slice into two large sheets to fit a 9x9 or 8x10 baking dish.
Start the sauce: Heat olive oil in a large skillet over medium. Sauté onion 3–4 minutes until soft. Add garlic and cook 30 seconds until fragrant.
Brown the beef: Add ground beef, salt, pepper, Italian seasoning, and red pepper flakes if using.
Cook, breaking it up, until browned. Drain excess fat if needed.
Add marinara: Stir in the no-sugar-added marinara. Simmer 5–10 minutes to thicken.
Taste and adjust seasoning.
Mix the ricotta layer: In a small bowl, combine ricotta, egg, and Parmesan. Stir until smooth.
Assemble: Lightly grease a 9x9 or similar baking dish. Spoon a thin layer of meat sauce on the bottom.
Lay down one keto noodle sheet. Spread half the ricotta mixture, then a third of the mozzarella. Add half the remaining meat sauce.
Second layer: Top with the second noodle sheet.
Spread the rest of the ricotta, another third of the mozzarella, and the remaining meat sauce. Finish with the remaining mozzarella and a sprinkle of Parmesan if you like.
Bake: Cover loosely with foil (tent so it doesn’t stick to cheese). Bake at 375°F for 20 minutes.
Remove foil and bake 10–15 more minutes until bubbling and browned in spots.
Rest and serve: Let the lasagna rest 10–15 minutes so it sets and slices cleanly. Garnish with chopped basil or parsley. Slice and serve.