Line a 4 x 8 inch loaf pan with a strip of parchment paper down the middle for easy removal.
In a medium bowl, mix the protein powder, oats, cocoa and salt. Pour in the tahini, maple syrup, mint extract, and chocolate chips and mix a bit with a fork and then get in there with your hands and work into a dough.
Press the dough firmly and evenly into the loaf pan and freeze for at least one hour. Lift the bars onto a cutting board and cut into four large or 8 small bars.
Store bars in a freezer bag in the freezer for up to 3 months.
For the best flavour and texture, wait 5-10 minutes (and up to 30!) before eating! Straight out of the freezer, they'll be less flavourful and have a drier (well, technically frozen, but it feels drier!) texture. The tahini gets creamier when it sits out a bit and it's really nice.
Notes
Want more of a snack size bar? Cut into 8 instead...each bar will still have 12g protein!