Preheat the oven to 180°C and grease a 20cm square cake tin.
Sift and mix the dry base ingredients in a bowl.
Rub in the butter until the mixture resembles breadcrumbs.
Add the milk and stir until the batter is smooth.
Spoon the mixture into the tin and bake for 20 minutes.
Allow the chocolate base to cool.
Combine the cherries, condensed milk, coconut, vanilla, and lime zest.
Spread the cherry mixture onto the base and bake for another 20 minutes.
Cover the cooled surface with melted chocolate and chill for one hour.
Cut the set traybake into squares to serve.