Preheat the oven to 350F. Spread the hazelnuts on a large, unlined baking sheet and roast for approximately 10 minutes until fragrant and a golden colour can be seen on the parts of the hazelnuts with no skin. Remove and cool completely before grinding fine.

Line two baking sheets with parchment paper or silicone baking mats and set aside.

In the bowl of a stand mixer with the whisk attachment or a large bowl with a hand held mixer, beat the eggs whites on high until very stiff. They should be so stiff that they pull away from each other when sliced with a sharp knife.

Add the sifted icing sugar and lemon juice and beat on high until mixture is stiff, holds its shape like stiffly whipped cream and does not move when picked up with a spoon (this takes approximately 2 minutes). Remove 3 tablespoons of this mixture into a small bowl and set aside.

Gently fold in the finely ground hazelnuts until evenly incorporated. Drop approximately 1 tablespoon sized mounds onto the lined baking sheets. The cookies can be spaced close together as they should not spread. Add approximately 1/4 teaspoon of the egg white/icing sugar mixture on top of each cookie and gently press one whole hazelnut on top (pointed side up). Let the cookies dry at room temperature until they are dull and dry to the touch (this will take a few hours). Best allowed to dry overnight.

Preheat the oven to 325 degrees F. Bake the cookies for 10 to 15 minutes or until light golden brown on the bottom and just barely golden on the white meringue on top. Let cool completely before removing from the baking sheets.

Store in an air tight container. These cookies also freeze well.