Some of these probably exist in Japan too, others probably don't.
If you're in the lab and want to try one of these, let me know and I'll gather ingredients and make it for you.
Brownie

Delicious and pretty common
----
Fudge

Sort of like brownies, but softer and richer.
----
Cookies

Well cookies they obviously have in Japan, but what about M&M cookies?!
----
Cupcake

Cupcakes are in the same class as brownies (very standard dessert snack).
----
Hershey's Kiss

Just a normal chocolate, but interesting shape and interesting name.
----
Roasted Marshmallows

Popular when camping, set up a campfire and roast marshmallows to golden-brown deliciousness.
----
Smore

Take a roasted marshmallow, put it in between two graham crackers and chocolate, and have a tasty treat. Substitute microwave for campfire if at home.
----
Pumpkin Cake

Popular during Halloween (due to it's pumpkin-ness)
----
Cherry Ice Cream

Popular during Summer when the cherries are especially fresh and delicious.
----
Banana Split

Only item on this list I've never had. It's an old-fashioned dish, and you would probably see it in movies set in the 1960-70s (Grease, etc). Looks really rich...
If you're in the lab and want to try one of these, let me know and I'll gather ingredients and make it for you.
Brownie

Delicious and pretty common
----
Fudge

Sort of like brownies, but softer and richer.
----
Cookies

Well cookies they obviously have in Japan, but what about M&M cookies?!
----
Cupcake

Cupcakes are in the same class as brownies (very standard dessert snack).
----
Hershey's Kiss

Just a normal chocolate, but interesting shape and interesting name.
----
Roasted Marshmallows

Popular when camping, set up a campfire and roast marshmallows to golden-brown deliciousness.
----
Smore

Take a roasted marshmallow, put it in between two graham crackers and chocolate, and have a tasty treat. Substitute microwave for campfire if at home.
----
Pumpkin Cake

Popular during Halloween (due to it's pumpkin-ness)
----
Cherry Ice Cream

Popular during Summer when the cherries are especially fresh and delicious.
----
Banana Split

Only item on this list I've never had. It's an old-fashioned dish, and you would probably see it in movies set in the 1960-70s (Grease, etc). Looks really rich...