Chopsticks: I'll need cutlery if I want to survive on a dessert island. I couldn't find any forks or spoons, so I'll just settle for a pair of these. I'm Asian, so I'm perfectly capable of eating cake and candy with chopsticks.
First Aid Kit: There's a couple of insulin shots in each of these, the last I checked. You'll definitely need them if you're going to be trapped on an island filled with sugary treats and delights. Why? 'cause diabetes, duh.
RPG Launcher: IF ANYONE TRIES TO SAVE ME FROM MY DESSERT ISLAND, I SWEAR TO GOD I'LL BLOW YOU OUT OF YOUR PRIVATE JET.