Grease and line a 20 cm (8") square baking tin and set aside (see my notes about alternatives).
Place sweetened condensed milk and butter in bowl and heat in the microwave until butter is melted then mix to combine.
250 g sweetened condensed milk, 100 g salted butter
Add crushed biscuits, grated lemon zest (see my notes), lemon juice and desiccated coconut then mix well to combine.
250 g plain sweet biscuits/cookies, 1 lemon - zest and juice, 85 g desiccated coconut
Tip base mixture into the tin, pressing down well to compact.
Frosting
In a small bowl combine icing sugar, lemon juice and softened butter.
300 g icing sugar (confectioner's sugar), 2 to 3 tablespoon lemon juice, 60 g salted butter
Mix well until thick and creamy and no lumps remain (add a little more lemon juice if too thick).
Spread frosting over base, sprinkle with extra desiccated coconut and place in the fridge to set.
1 tablespoon desiccated coconut
Notes
A reminder to zest the lemon before you juice it, I forgot once - not easy to do it in the other order!
When grating the lemon for the zest, it's important to only use the outer yellow part of the rind. The white "pith" just underneath the yellow rind is bitter.
Even though this is an unbaked lemon coconut slice, we still need to grease and line the tin with baking paper (leaving extra baking paper overhanging the sides). This helps us get the slice out of the tin once it's set.
If you don't have a tin the same size as I use in this recipe, a little bigger or smaller is still ok. The slice will just come out with layers a bit thicker or thinner. Still tastes just as good!
Also, there's no need to limit yourself to a baking pan or tin. Because this is a no bake slice you could set it in a plastic container if it's the right size.
Having trouble getting the slice out of the tin? Just sit the base of the container in hot water for a few seconds then it should come out easily.
I use a food processor to crush the biscuits for this lemon coconut slice. If you don't have one, just pop them into a plastic bag and bash them with something heavy like a rolling pin or the flat side of a meat mallet. You want to achieve fine crumbs.
*Please note that the amount of calories per serve is provided as a guide only, as ingredients and cooking methods can vary greatly*