Preheat oven to 375 F. Heat a large pot of salted water over high heat until boiling, then add lasagna noodles. Cook for 8-9 minutes until al dente, then carefully remove each noodle with a pair of tongs (I recommend tongs with a rubber/silicone end instead of metal), then place noodles on a greased baking sheet lined with parchment. Coat some of the noodles with a bit of olive oil to prevent them from sticking together as you'll have to stack them on top of each other. Do not drain the water.
Once all pasta is removed, add spinach to the boiling water, cooking for 30 seconds until wilted. Drain then squeeze excess liquid out of the spinach once cooled with a spatula by pressing the spinach in the strainer.
Meanwhile, heat a large skillet over med-high heat. Add ground beef, breaking up with a spatula, and cook for 5 minutes until browned. Add onions, cooking another 5 minutes until softened. Add garlic, cooking 1 more minute, then remove from heat.
In a large bowl, mix ricotta with egg and cooled spinach. Now you're ready to assemble your roll ups!
Add olive oil to the bottom of a 9x13 baking dish, greasing well, then add a bit of the pasta sauce (about 1/2 cup).
Spread each lasagna noodle with a bit of ricotta and ground beef mixture (it should be about 2 tbsp of each). Carefully roll noodle up and place in the greased baking dish. Repeat for remaining noodles. There will be a total of 12 roll ups in the end.
Cover roll ups with remaining pasta sauce, then add cheese overtop. Bake for 30 minutes until cheese is melted. Serve garnished with fresh basil or parsley and enjoy!