- Grease and line a 17 x 27cm slice tin with baking paper, leaving an overhang on all sides. Place biscuits in a food processor and process to form fine crumbs.
- Transfer the mixture to a bowl, then combine with coconut and finely grated zest of 1 lemon from one lemon. Place butter in a small saucepan over medium heat to melt. Stir in condensed milk. Pour melted mixture over the dry ingredients. Stir to combine well.
- Press biscuit mixture into prepared tin. Refrigerate for one hour or until firm. When set, ice with lemon icing.
- To make lemon icing, place the icing sugar in a bowl. Add melted butter and lemon juice of 1 lemon and beat until smooth.