Chop 1.3 oz (50 g) dark chocolate into small pieces. I did not do that and my chocolate took time to melt.
Keep one bread slice on a board and spread half of the dark chocolate over it.
Drizzle 2 tablespoon chocolate syrup and sprinkle 2 tablespoon chopped toasted walnuts on top.
Cover with another bread slice.
Slather butter on both sides (1 teaspoon on each side) of the sandwich.
Make the other sandwich in the same manner.
Grill the sandwiched until browned and crispy in a sandwich griller or on a skillet over the stovetop. Cut into half using a sharp serrated knife.
Top with ice cream scoop, chocolate syrup, shredded chocolate, and sliced banana and serve warm.
I would suggest you use white sandwich bread or milk bread slices, as I feel they taste the best when used for this chocolate sandwich. They are soft, have a slightly sweet taste, and become really crispy when grilled. Brioche is another great option too.You can also use other nuts such as almonds, cashews, pistachios, or a mix of dry fruits to add to the sandwich.