I like making homemade meatballs when I can because I think they taste much better than pre-made meatballs. I was pleasantly surprised with how fast I could whip these up. I made them for my husband and his reaction was worth more time than I actually had to spend. He LOVED them.
Mix all ingredients except the mozzarella cheese and tomato sauce in a large bowl. Mix together thoroughly. Portion the meat mixture into meatballs. I use a stainless steel cookie scooper to evenly portion the meatballs. I don't worry about packing the meat until I insert the mozzarella.
Cut the block of mozzarella into 1/2" to 3/4" cubes. This recipe makes about forty-five 1-1/2" meatballs. Cut enough cheese to be able to insert one cube into each meatball.
Insert a cheese cube into the middle of each meatball. Pack the mixture tight. Arrange the meatballs in a slow cooker. My casserole slow cooker worked perfectly for this recipe. Pour the can of tomato sauce over the meatballs. Cook on high for 2 to 2-1/2 hours.
* Cook's Note - Obviously, the hot Italian sausage will add some spice to the meal. If you don't care for spicy food, replace the hot sausage with mild.