Add the 2 pounds ripe peaches, ½ cup granulated sugar, Juice from ½ lemon, 1 teaspoon vanilla bean extract or paste, and ⅛ teaspoon ground cinnamon to a crockpot. Stir to combine.
Cover and cook on low for 6 to 8 hours or high for 3 to 4 hours, until the peaches are very soft.
Blend with an immersion blender until smooth. Leave the lid slightly ajar and cook on high for 1 to 2 hours more, stirring occasionally, until thick and spreadable.
Taste and adjust the vanilla bean paste or cinnamon as desired. Cool completely, then transfer to clean jars and refrigerate.