Prepare the peaches: Peel, pit, and halve the fresh peaches. Place them directly into a large slow cooker insert.

Combine wet and dry ingredients: In a separate bowl, whisk together the brown sugar, cinnamon, nutmeg, and cloves. Sprinkle this mixture evenly over the peaches in the slow cooker.

Cook on low: Pour the 1/2 cup of water and add the lemon juice over the peaches. Cover the slow cooker and cook on LOW for 6 to 8 hours, or until the peaches are extremely tender and break apart easily.

Blend until smooth: Carefully transfer the cooked peach mixture to a food processor or blender (or use an immersion blender directly in the crockpot). Blend until the mixture is completely smooth and resembles a thick sauce or butter consistency. Work in batches if necessary.

Thicken (Optional): If the mixture seems too thin after blending, return it to the slow cooker (without the lid) and cook on HIGH for another 30 minutes to an hour, stirring occasionally, until it thickens slightly. It will thicken significantly more as it cools.

Cool and store: Allow the peach butter to cool completely before transferring it to airtight jars. Store refrigerated for up to 3 weeks, or freeze for up to 6 months.