Combine apples, cranberries, brown sugar, maple syrup, orange juice, lemon zest, cinnamon, ginger, and salt in the crock pot.

Cover and cook on low for 2–3 hours, or until apples are tender and mixture is jammy; stir once halfway.

Mash slightly with a potato masher for a rustic texture, then stir in butter if using.

Keep warm on the warming setting until ready to serve with cheeses, crackers, and nuts.