Pour the honey and sugar into a medium saucepan and heat gently until sugar dissolves. Bring mixture to a boil to form a caramel then remove from the heat.
Stir the peanut butter into the saucepan and mix until the mixture is smooth.
Place the crispy rice into a large bowl and pour the peanut butter mixture over and mix thoroughly until all the crispy rice is covered.
Scrape it all into the cake tin evenly and press down so the surface is smooth and packed in.
Meanwhile melt the chocolate with the coconut oil and salt in a bain marie or bowl set over a saucepan of simmering water.
Once the chocolate has melted, pour over the peanut butter crispy rice base into an even layer, tilting the tin to make sure it goes right to the edges. Scatter some sprinkles on top and place in the fridge to set for a couple of hours.