Rinse quinoa under cool water using a fine mesh strainer. Combine with water in a saucepan, boil, then simmer for 15 minutes until fluffy. Cool.

Mix peanut butter, maple syrup, and vanilla extract in a bowl until smooth. Fold in cooled quinoa.

Melt dark chocolate chips and coconut oil in a microwave-safe bowl; stir every 30 seconds until smooth.

Line muffin tin with paper liners. Pour 1 tablespoon melted chocolate into each, swirl to cover the bottom. Freeze for 10 minutes.

Once chocolate is hard, spoon quinoa filling into each cup, pressing down gently.

Cover with remaining melted chocolate, smooth out if needed. Freeze for 15-20 minutes until solid.

Remove from muffin tin, sprinkle with sea salt or nuts if desired. Store in an airtight container.