In a big bowl place the butter and the sugar and mix them well. After that, add the egg yolk, the cognac, the baking soda and the vanillas. Mix them well until it becomes a smooth mixture. When the mixture is ready, add the two cups of almonds. In another bowl, place the flour and the baking powder and then add the mixture that you already created in the first bowl. Mix all of your ingredients well. After that, cut small pieces of your mixture and shape in in any way you want. When you finish, place your shortbreads in the oven. When you finish baking, add on the top of your shortbreads as much powder sugar as you want.