They are time-consuming and require a lot of steps which I spread over about two days, but the reception they got made it worth every minute. This instructable will tell you how I made them.
Step 1: Planning & Ingredients
1. Cake. You will need a sheet cake, which I made using King Arthur Flour's Elegant White Cake recipe, with the only change being the substitution of virgin coconut oil (which I had in the pantry) for the vegetable shortening (which I think is gross). I don't buy cake flour, but make it like this with much success.
2. Pastry cream (or frosting). Since my cake recipe calls for five egg whites, I elected to make pastry cream (instead of frosting), which requires five yolks. The Brown-Eyed Baker's recipe is excellent and hasn't failed me yet. Pastry cream is super fun to make, not overly sweet, and marvelously smooth. But you can use frosting if you prefer. You will have extra whichever route you choose; with pastry cream, you can make cream puffs or fruit tarts. If you're a frosting fan, I guess you can just eat it with a spoon.
3. Fruit. I used raspberries, a kiwi, some mango, and a peach.
4. Chocolate. Rather a lot of it, like possibly most of a bag of nice quality chips.
5. Shredded coconut, sweetened or unsweetened according to your preference (I go with unsweetened).
6. Glaze. Mine required the juice of one lemon, about a quarter cup of brown sugar, and a dash of dark rum. The glaze keeps your cut fruit from browning, so don't skip it.
1. Parchment paper
2. A half-sheet pan (if you're making the cake) and sauce pan (for the pastry cream) and bowls and all that
3. A small biscuit cutter
4. A small sauce pan for the glaze and a brush
5. Surfaces to put your sushi on going in and out of the fridge, and something to cover them with
6. A chocolate-melting apparatus, such as a double-boiler or a dish that sits on a sauce pan
7. A round pastry tip with coupling (pastry tips are cheap to buy individually, fun to use, and they take up almost no storage space so there's no reason you shouldn't have a couple) and a brand-name zip-top bag (the cheap-o ones will burst under the pressure of the cream - this has happened to me; just buy the good bags). Snip the corner from the zip bag and attach your pastry coupling to it.