Preheat oven to 180 degrees C. Grease and flour a baking tray.
In a large bowl, stir together flour, sugar, baking powder, salt, almonds and orange zest. Make a well in the centre and add the eggs, oil and almond essence. Stir or mix by hand until the mixture forms a ball.
Separate dough into 2 pieces and roll each one into a log about 20cm inches long. Place logs on prepared baking tray and flatten so they are about 2cm thick. Bake in preheated oven for 20 to 25 minutes. Cool slightly, and remove from baking trays. Slice diagonally into 1cm slices with a serrated knife. Set biscuits back onto the baking tray and bake for 10 to 15 more minutes, turning over after half of the time. Finished biscuits should be hard and crunchy.