Place the sliced zucchini on a sheet pan seasoned with salt and pepper. Make sure to either use parchment paper or spray the tray with olive oil. Also, lightly spray the zucchini. Bake on 400 F for about 8 minutes until they are just tender and easy to roll. Take out and let it slighlty cool.
In a baking dish, about 9x11 in size, add the tomato sauce to the bottom of the pan spreading it out evenly.
In a pan, add the olive oil and mushrooms. Sautee with salt and pepper until mushroomms are soft. Place this on top fo the tomato sauce. Mix together.
At this point, work on the filling. Just combine all its ingredients into a bowl and mix together very well until its one cohesive creamy filling.
Take a slice of the zucchini. Add 1 big spoonful of filling a few inches from the end of the zucchini slice. Then, roll the bottom over the filling and keep on rolling. It is okay if some filling oozes out. Place this on top of the sauce mixture. Repeat with the rest of the zucchini slices.
If you have extra ricotta filling, either add it to the baking pan or save it for future use in your fridge kept in an airtight container.
Top the zucchini roll ups with the mozzerella cheese. Bake in a 400 F oven for about 10-15 minutes until cheese has melted. Then broil for a minute. Enjoy warm as is!