I don't like a lot of sugar in mine since the apples cook down and become fairly sweet, but be sure to taste along the way and adjust to your tastes. Apple butter also freezes wonderfully.
3 1/2 lbs apples, peeled, cored and sliced
1/4 cup light brown sugar
1 teaspoon cinnamon
Put apples into the crockpot, cover and set on high (you can also do this on the stovetop over low heat if you prefer or don't have a crockpot, I like using a crockpot for this because it doesn't have to be watched carefully and I can get other things done while it cooks). Let cook, stirring occasionally, until apples have completely broken down, about 3 1/2 hours.
Add cinnamon and sugar, stir until well combined and allow to cook for 1 1/2 more, stirring every once in a while. If you like a smooth apple butter (which I do!) use an immersion blender until mixture is very smooth, if you like some texture to it, skip this step.
Switch temperature to low. Cook for another 3 1/2 hours until the apple butter has darkened and thickened.
this recipe can also be found at some of my favorite food blog hops