Combine the apples, pears, honey (you can leave this out and still get delicious sauce), water, lemon juice, and ginger in the slow cooker. Cover and cook until the fruit is extremely tender and falling apart, on low for 5 hours
Beat to make a corse mash or use a food processor for a smoother sauce (don’t over blend). Stir in the butter. Serve immediately or refrigerate and serve cold.