Tip the raw rice into a deep cake tin and cover the top with cling film.
Crumble the sponge into a food processor and dollop in the melted dark chocolate.
Blitz until mixed.
Scoop out tablespoons of the mixture and roll into lolly shapes between your hands.
Gently poke a lolly stick or skewer in about halfway, then stand up in the rice, and chill for 2-3 hours until completely firm.
Melt the white chocolate in a bowl over a pan of barely simmering water then remove from the heat and cool for 1-2 minutes.
One by one, dip the chocolate lollies into the white chocolate to coat, then let the excess drip back into the chocolate bowl.
Stand the lollies in the rice-filled cake tin.
Tip the decorations into small bowls, then dip the lollies in, gently rolling them around and coating them.
Chill again for 1-2 hours, or overnight, until the chocolate is hard and set.