Cook & drain noodles. Brown & drain Ground Chuck.Add spaghetti sauce, Italian dressing mix, & mushrooms to cooked ground chuck.
In large Crock Pot, place 1/3 of cooked noodles. Next add 1/3 of meat sauce, then 1/3 of cheese. Lastly add 1/3 of sliced pepperoni. Repeat layers two more times. Ending with the third layer of cheese on top.
Cook this on high in your Crock Pot for 2 hours or until the cheese on top is melted.