Citrus Slice

Prepare a 23cm square tin with baking paper, I spray baking spray first to help paper stick (size will impact height of slice so up to you!)Zest the lemon and orange using a fine grater and set asideJuice both the lemon and the orange together, drain the juice and set aside.Melt the condensed milk and butter together, either on the stove top gently or in the microwave in 30 second bursts in a covered microwave proof bowl, until butter completely melted.Crush the biscuits into a fine crumb (see above for methods)Add the coconut, melted butter/condensed milk mixture to the food processor and blend well.Add half the prepared zest to the base and 1 TBSP of juice to the base mixture and combine well.Pour the base mixture into the prepared tin, smooth out with the back of a spoon or your hand and refrigerate.In a medium bowl add the icing sugar, remaining zest and melted butter and gently stir.Add the remaining citrus juices a teaspoon at a time, mixing well, until you have the desired consistency, you may use an extra lemon for its juice or water if not wet enoughPour the icing over the base once slightly cooled and spread evenlySprinkle with citrus zest or coconut and return to the fridge overnight or for at least 2 hours before slicing with a sharp warm knife to serve.Store in an airtight container.