1. Mix chia seeds, maple syrup, vanilla extract and yogurt in a medium bowl.
2. Line a 13” x 9” baking sheet with parchment paper. Evenly spread the yogurt mixture on the baking sheet.
3. Transfer to the freezer for at least 4 hours, or until completely frozen.
4. When ready to serve, remove from the freezer and lift out the parchment paper. Cut the bark into pieces.
Eat immediately or store in ziploc bags in the freezer.