First, bring a large pot of salted water to a boil. Add lasagna noodles.
Cook the lasagna noodles until they have a bit more of a bite than al dente. They are going to continue to cook in the oven.
Strain the water from the noodles and rinse the noodles with cold water.
Lay the noodles out flat on a baking sheet or on top of parchment paper and drizzle the noodles with oil. Set the noodles aside for later.
Next, heat a Dutch oven over medium/high heat. Add the ground beef.
Sauté the beef for 3-4 minutes and then add the onion and garlic to the meat.
Cook for an additional 2-3 minutes.
Add the spinach to the skillet, toss, and cover. The spinach should wilt within 2-3 minutes.
When the spinach is wilted, remove from heat and set aside.
Next, add the ricotta cheese, 1 cup mozzarella cheese, 1/4 cup parmesan cheese, fresh thyme, garlic powder, and salt to a large bowl and mix until combined.
Add the spinach mixture to the cheese mixture and fold the spinach mixture into the cheese mixture until everything is combined.
Preheat the oven to 350ºF and spray a 9×13-inch baking dish with cooking spray.
While the oven is preheating, assemble the lasagna roll ups.
Pour 1.5 cups of the marinara sauce in the bottom of the casserole dish and spread the sauce out on the bottom of the dish.
Next, spread 2 heaping tablespoons of the cheese and spinach mixture across the length of the whole lasagna noodle and then slowly roll the lasagna into a lasagna roll up.
Place the roll up in the casserole dish on top of the marinara sauce. Repeat step 13 until you have 12 lasagna roll ups lined up in a 9×13 casserole dish.
Pour another 1.5 cups of marinara sauce over the lasagna roll ups.
Place the lasagna roll ups in the oven and bake the lasagna rolls at 350ºF for 25 minutes. Sprinkle 1/4 cup parmesan and 1/2 cup mozzarella on top and bake again for 5 more minutes.
Remove from the oven and let the lasagna roll ups sit for 5 minutes and then enjoy.