Slice the watermelon into 2 cm thick pieces (0.8 inches).
Use the flower cookie cutter to shape the watermelon (you can make two sizes like I've done, or stick to one size).
Place the watermelon flowers on a kitchen towel to dry off (this will help the chocolate stick better).
Slice a similar thick piece of mango and trim off the outer skin.
Make the round mango cutouts with the round cutter.
Now, cut out the center of the watermelon flowers with the round cutter.
Place the mango pieces into the middle of the melon flowers.
Melt the dark chocolate.
Place the chocolate in a piping utensil or bag.
Using a pencil, trace the inside of flower cutters onto parchment paper.
Turn the paper over.
Pipe melted chocolate over the outline of the flowers (you can also cover the entire base of the flowers if you prefer).
Place the watermelon flowers on top of the chocolate and press down so the chocolate spreads out.
Allow to set.
Stick a skewer into the flowers (this will keep the mango piece in place).
Serve.