Place shark fin template on a sheet tray and a sheet of parchment paper on top. Pipe shark fins with the grey royal icing. Let dry completely, 4-6 hours. When set, carefully remove with a small offset spatula.
Preheat oven to 450 degrees F and line a baking sheet with parchment paper.
Lightly flour a surface and unroll pie dough. Cut four circles using a 4 1/2 inch cutter. Roll out scraps and cut two more circles. Repeat with other roll of dough. You should have 12 dough rounds total.
Place half the rounds on the prepared baking sheet. Top each round with 3 tablespoons of cherry pie syrup, making sure to leave a border.
Brush the borders with some water. Top with dough rounds, pressing to adhere. Crimp with fork.
Cut 2 small slits the tops with a knife. Beat egg with a splash of water and brush tarts with egg wash.
Bake for 10-13 minutes, until golden brown.
Add chocolate to a microwave-safe bowl and microwave in 30 second intervals, whisking in between, until melted. Transfer to a piping bag.
Pipe the outline of a circle onto a tart with the candy melts. Fill it in and spread with a small offset spatula. Press four shark fins, upright, into the candy melts. Sprinkle fish in the center. Repeat with remaining shark tarts. Can serve either warm or let chocolate set completely.