Preheat the oven to 180°C and line a 30x23x4cm baking tin with overlapping aluminium foil.
Mix lime juice, zest, spices, and desiccated coconut in a bowl to soak.
Sift the flour and baking powder into a large bowl.
Pulse sugar, butter, and coconut butter in a food processor until smooth.
Mix the butter mixture into the dry ingredients and fold in the eggs and soaked coconut.
Spoon the batter into the tin and bake for 30 minutes until a skewer comes out clean.
Cool in the tin for 5 minutes then transfer to a wire rack to cool completely.
Pulse the icing ingredients in a food processor until smooth.
Spread icing over the cooled cake, trim the edges, and cut into 12 squares.
Roll out fondants and cut 48 green leaves and 12 brown trunks.
Decorate squares with fondant trees and chocolate bean coconuts and sprinkle with lime zest.