Wash and slice whole apples with skin on and place in a slow cooker. Discard the apple cores.
Use as many or as few apples as you want filling the slow cooker. This will depend on how much apple sauce you wish to make.
Cook for 8 hours on low heat.
Place softened apples in a blender and blend just enough to make an apple sauce texture.
Pour blended apples to a large cooking pot and place on the stove top. Add cinnamon and mix. Cook over medium heat for one hour.
Place in sterilized jars or if only making a small batch, place in a sealed container and store in the fridge to enjoy within the week.
If canning the apple sauce, cover jars with sterilized lids and place back in the oven for 30 minutes to hour and 220F to help seal.
Sauce has to be hot when it goes in the jar.