1. Place mangos and dates in a large bowl or glass measuring cup, and cover with hot tap water. Let sit for 15 minutes to soften.
2. Drain dates and mangoes, then put them in the bowl of a food processor or high-powered blender (I used my Vitamix). Blend until almost thoroughly puréed, about 1-2 minutes.
3. Add all remaining ingredients and pulse just to combine. The batter should be soft and sticky.
4. Pour a little extra almond meal and/or hemp seeds in a small bowl. Scoop batter with a mini ice cream scoop, or a spoon, and drop into the bowl of almond meal, stirring to coat. Use your palms to roll each dollop of dough into a ball. Repeat until all the dough has been used up.
5. Store balls in an airtight container in the fridge for up to 1 week. These energy balls will remain soft and sticky, and only slightly harden after refrigeration.