Preheat oven to 400 degrees. Lay out puff pastry sheets to thaw (30 minutes).
Heat small saucepan over medium heat. Add the cocoa powder, brown sugar, milk, salt, and the milk chocolate. Stir until the chocolate is melted, cooking at a low boil for five minutes.
Remove pan from heat and add the vanilla and peppermint extracts. Set aside to cool and thicken.
Whisk together the milk and egg for the egg wash. Set aside.
Lay out thawed puff pastry sheets. Cut each sheet into three vertical rows. Stack the rows on top of each other and cut in half to form six equal sheets. Repeat with second puff pastry sheet.
Brush egg wash along outside rim of one puff pastry square. Spoon filling on top. Pinch edges with fingertips, then crimp with fork.
Bake for 15-20 minutes until the pastries are golden brown. Set aside to cool.
Mix together the milk and powdered sugar for the glaze until desired consistency is reached. Add food coloring of choice.
Drizzle glaze over cool pop tarts and enjoy!