On a large baking sheet, add 12 cream crackers.
Add 1 round slice of ham and 1 slice of mozzarella on top of each cracker.
Top everything with 12 more crackers and set aside.
Next, in a small jar, add the butter, the soy sauce, the Dijon mustard, the garlic powder and mix everything to combine.
Pour this mixture by spreading it all over the cracker sandwiches.
Finish with black sesame seeds to taste.
Take to a preheated oven at 180° C (350° F) and bake for 15 minutes.
Serve.