Before you start this recipe, preheat oven to 170`c. In a bowl, combine together the flour, sugar, baking powder, cinnamon and almonds. In a separate bowl, whisk together the eggs and vanilla and fold into the dry ingredient mixture. It is important that you keep mixing until you obtain a stiff dough. Split the dough in half and shape into two equal size logs. Place logs on lightly greased baking sheet and cook for 25 minutes or until firm. Remove the logs from the oven and allow to cool for 5 minutes before cutting into 1/2 inch wide diagonal slices to form the biscotti. Place the biscotti on a sheet and bake for a second time for a further 9 minutes. Turn over the biscotti and continue to bake for 8 minutes. This process will help to dry out the biscotti and make them nice and crunchy.