My cabinets are 12 inches deep. There is a 3/4 inch piece on the front that the doors are attached to. So, with the door closed there is about 12.5 inches of useable space.
I guess we were lucky to have had the deeper cabinets in the first place!
I am making my incredible pizza stuffed mushrooms for dinner - you can stuff small mushrooms but I bought large Portabellas - you mix cream cheese (I’m using jalapeno flavored), chopped pepperoni, cooked sausage(I buy already cooked crumbles from Jimmy Dean), and chopped black olives... mix in a little shredded cheese (I’m using smoked gouda) pile the toppings on the portabella and pour some marinara sauce all around and bake for about 30 minutes or until the mushrooms are soft.