Cream the butter and sugar together. Add the egg and beat well. Mix in the flour, baking powder and salt to form a well-kneaded dough. On a smooth floured surface roll out and cut circles to line the cups of a cupcake or muffin tray.
Prick the bottoms of the tart cases with a fork a couple of times each. Bake for 10 to 15 minutes. Let them cool entirely on a cake rack before adding the filling.
Soften the butter and mix in icing sugar, condensed milk and lemon juice. Fill the tart cases with this mixture and allow it to set. Chilling helps.
Add a little hot water and melted butter in a bowl then keep mixing in icing sugar until it reaches the desired consistency. To make a chocolate one add a little cocoa as well as the icing sugar.
Once the filling has set add the plain and chocolate icing in patterns on top of the tarts.
The origin of the name "neenish" is unknown, though a column in the Sydney Morning Herald attributed the name to a Mrs. Ruby Neenish. Alternative names such as nenische (recorded in 1929) and nienich (recorded in 1935) suggest a German origin, although neenish was known before the alternatives, suggesting these names were to give a "continental" flavour to the tart.
All in all, a true treasure that deserves to be made properly. Eat these and you will never touch mass produced Neenish Tarts again. - 05 Dec 2012