Lemoenvierkantjies (Orange squares)

This is a nostalgic recipe for me. My mom used to make it for celebrations as a sweet treat, and it was her usual contribution for school events or other socials where she was asked to bring something sweet. Somehow this recipe is almost impossible to find on the internet - a search for it gave me a whole lot of nothing, except for others asking about it. So I asked my mom for hers, and here it is:

Ingredients:
Base:
1 and a half to 2 packets of marie biscuits
1 cup sugar
Juice and rind of one orange
1 tin of condensed milk (300g)
1 cup butter
2 cups coconut

Topping:
2 cups icing sugar
Juice and rind of 3 oranges
1 T butter

Method:
Crush the biscuits.
Heat together the condensed milk, butter, sugar, juice and rind until the sugar is melted. Add the biscuits and coconut and mix through.

Put all together in an oven dish or baking tray. Let cool but not until cold. While it cools, mix the topping and pour over the base. Cut into squares before it cools too much; it will harden as it cools. Store in the fridge