Peel peaches, remove pit and cut into chunks or slices and place in a 6 quart or larger crock-pot.
Cut each vanilla bean in half lengthwise and scrap out the vanilla bean seeds with a spoon and put seeds and the pods into the crock-pot with the peaches.
Add the sugar and stir to combine.
Cover and cook on low 4 hours.
Remove the vanilla bean pods.
Pour cooked peaches into the jar of a blender and cover.
Carefully (the mixtures will be hot!) blend the peaches until smooth.
Pour pureed peaches back into crock-pot and cover, but prop up the lid of the crock-pot with a chopstick or other heat proof utensil to allow moisture to escape.
Continue cooking on low for 1-2 hours, stirring every now and then to prevent peach butter from burning.
Pour into jars or containers and refrigerate for up to 2 months, freeze for up to 6 months or process in a hot water bath for 20 minutes.
