Step 1: Get the oven ready

Preheat the oven to 425°F.

Step 2: Combine ingredients

In a large skillet, heat 1 tablespoon of olive oil over medium heat. Add the garlic and red pepper flakes and cook until fragrant (about 30 to 60 seconds), then toss in the baby spinach. Sprinkle with the salt and saute until the spinach has wilted, about one to two minutes. Remove the spinach from the skillet and combine it with the ricotta cheese in a mixing bowl, then set aside.

Step 3: Cook the pasta

Bring a large pot of water to a boil. Once boiling, toss in the broken pasta pieces and cook the pasta until al dente—about four to five minutes. Drain and set aside.

Step 4: Cook the sausage

While the pasta is cooking, heat another 2 tablespoons of olive oil in that same skillet over medium heat and cook the sausage for about five minutes. Toss in the onions and cook for another three minutes. Remove the skillet from the heat.

Step 5: Add the sauce

Add the marinara sauce, half a cup of pasta water, cooked pasta, 1 cup of mozzarella cheese and ½ a cup of parmesan cheese to the skillet. Stir to combine.

Step 6: Assemble the lasagna

Spread the mixture onto a 12 x 17-inch baking sheet. Add dollops of the ricotta-spinach mixture on top. Sprinkle the tops with the rest of the mozzarella and parmesan cheese.

Step 7: Pop it in the oven!

Bake in the oven for 30 minutes or until the sauce is bubbly and the top lightly browned. Scoop onto plates and enjoy, maybe with a simple lettuce salad on the side!