To make prune puree: In blender, combine prunes and water. Pulse to combine then blend until smooth, pourable consistency forms, scraping sides, if necessary.
Store puree in airtight container in fridge up to 4 weeks.
To make energy balls: In mixing bowl, stir oats, coconut, nut butter, pecan meal, prune puree, cocoa powder and vanilla until completely combined.
Cover and chill in refrigerator 30 minutes. Once chilled, use small cookie scoop or measuring spoon to measure equal-sized amounts of mixture then form into balls by applying gentle pressure to dough using palms. Do not roll as balls will break apart.
Store covered in airtight container in refrigerator up to 1 week.