In a medium bowl combine the oats, cereal, protein powder, flax, salt, peanut butter, honey, coconut oil, and vanilla. Stir to combine well or mix with hands. The dough should stick together easily. If not, add 1-2 teaspoons of water at a time until dough sticks together.
Line a pan with parchment paper so that paper overlaps edges. Transfer the dough to the pan. Spread the dough out evenly and with your hands press dough very firmly into the pan. Place the pan in the freezer.
After bars have been in the freezer, remove the bars from the pan by grabbing onto the parchment paper flaps, lift them out, and place on a cutting board. Drizzle the melted chocolate evenly over the bars. The chocolate should harden quickly since the bars are cold.