Preheat the oven to 350 degrees. Coat an 8 x 8-inch baking dish with olive oil cooking spray.
Make the ricotta mixture by combining the ricotta cheese, basil leaves, 1/4 cup of parmesan cheese, egg, garlic, sea salt, freshly cracked pepper, and crushed red pepper flakes in a small bowl; mix until well combined.
Prepare the lasagna by spreading 3/4 cup of marinara sauce evenly across the bottom of the pan.
Next, layer 3 lasagna noodles in an even layer, followed by half of the ricotta mixture, 1/2 cup of mozzarella, and 1 cup of spinach.
Repeat with a second layer of 3/4 cup marinara, noodles, remaining ricotta mixture, 1/2 cup of mozzarella, and remaining cup of spinach.
Finish the final layer with 3/4 cup marinara, noodles, 3/4 cup marinara, and remaining cup of mozzarella.
Cover the baking dish with foil and bake for 20 minutes.
Remove the foil and bake for an additional 15 minutes until the cheese is melted and starts to brown around the edges.
Remove and set on a cooling rack for 10-15 minutes before slicing and serving.
Top with freshly grated parmesan and chopped parsley. Enjoy!