5 pounds apples, cored and chopped into chunks (no need to peel them)
1½ cups apple cider vinegar
1½ cups maple syrup
2 tablespoons cinnamon
Preheat oven to 375°F. Combine all ingredients in a large pot, cover and simmer over medium heat on the stovetop for 15 minutes or until apples are very soft. Blend the contents until very smooth, either with a high-powered immersion blender or in a Cuisinart.
Next, transfer the purée into two 15-by-10- inch glass baking dishes, filling them halfway full. Place the baking dishes in the oven and bake until the purée cooks down to about half the volume and the sugars become brown and caramelized. This can take anywhere from 3–5 hours, depending on how juicy the apples were to start, how sweet they are and how humid the air. Stir the purée occasionally by folding in the top layer and scraping down the sides. You can test the apple butter by placing 1 teaspoon of it on a plate and cooling it in the freezer. The butter should not have any liquid separate from it and should sit tall in a nice pile.
When finished, ladle the apple butter into 8-ounce jars and process in a hot water bath canner for 8 minutes. Fruit butter will keep for two years. Yields 7, 8-ounce jars.