Brew a cup of cappuccino and combine it with cornstarch in a medium saucepan.

Whisk over medium-low heat until the cornstarch is dissolved.

Whisk in milk, sugar, and cocoa powder.

Increase the heat to high and whisk for 1-2 minutes after bringing to a boil, until the mixture is thick.

Pour the pastry cream into a square baking pan and cover with plastic wrap pressed tightly to the cream.

Refrigerate for 4-6 hours.

Prepare a dredging station with beaten egg and graham cracker crumbs mixed with panko.

Heat oil to 350F on the stovetop or in a deep fryer.

Remove pastry cream from the refrigerator and cut into squares.

Dredge each square in egg, followed by the graham mixture.

Fry in hot oil until golden brown.

Remove with a slotted spoon and place on a paper towel.

Toast jumbo marshmallows in the oven or with a kitchen torch.

Place pastry squares on a plate or chocolate bark and top with toasted marshmallows.

Serve immediately.