I'm starting at a new school as a trainee science teacher and there is a tradition of baking or bringing in buns, cakes etc. on special occasions. For my first 'special' day I was thinking of baking some 'Lithium buns' which seems especially appropriate for the first day of term. Each bun would have 3 blackcurrants and 4 redcurrants in the center, topped with 3 chocolate chips. Any other ideas for science related treats?