Preheat oven to 200 degrees C. Cream the butter and sugar until light and fluffy. Add egg yolks and mix well. Pour in the oil, ouzo and baking powder.
Slowly fold in the flour a bit at a time. You may not need all the flour; the dough needs to be light and not sticky. Do not overwork the dough as this can make the kourabiedes tough.
Take a small handful of dough and shape into crescents. Place them onto a baking tray.
Place the slivered almonds in a clean frying pan and toast them over a low heat on the stove top until slightly golden. Sprinkle over the dough.
Bake for about 20 minutes, or until golden brown.
Remove from the oven and, using a spatula, transfer onto greaseproof paper. When they are cool, dust with plenty of icing sugar and transfer onto a platter.
These biscuits keep well for about 3-4 weeks.
