In a medium pot put water in to cook the rice and bring it to a boil.

Put a large stockpot of water on the stove (for the cabbage leaves) and bring it to a boil.

Wash the head of cabbage and remove the cabbage leaves from the head.

Once the water is boiling in the medium pot add the rice and cook according to the package.

Once the water in the stockpot is boiling add the cabbage leaves to the boiling water and cook until the leaves are tender and pliable.  This will take about 4-7 minutes depending on the thickness of cabbage leaves. Once the cabbage leaves are cooked, use tongs to remove cabbage from water and set aside on a paper towel lined plate to drain and cool.

While the cabbage and rice are cooking, cook the ground beef in a large skillet until cooked, stirring regularly. Once the ground beef is cooked, remove from the heat drain and stir in the salt, pepper and garlic powder and mix it well.

In a large bowl, mix chopped zucchini, diced onion, cooked rice, and ground beef and mix well.

Spray non stick cooking spray on the bottom of the Crockpot or slow cooker.

Pour a small amount of tomato sauce on the bottom of the crock pot, just enough to cover the bottom.

Fill the cabbage leaves with the beef, rice and veggie mixture and wrap them closed.

Place cabbage rolls into crock pot one at a time as you make them and stack them on top of each other.

Pour the can of diced tomatoes on top of the cabbage rolls once they are all in the crockpot, then pour the rest of the tomato sauce on top of the cabbage rolls.

Cook on high for 4 hours or low for 6 hours.

Sprinkle grated Parmesan cheese on top of the cabbage rolls when they are done cooking.