Add sugar and vanilla to egg whites in mixing bowl. Whisk until stiff peaks form, about 8 minutes.
Let rest 30 minutes.
Heat oven to 280°F.
Gently fold in ground hazelnuts.
Drop by teaspoons full on to parchment lined cookie sheet. Place whole hazelnut in center of each cookie.
Place cookie sheet in oven. Let the meringues dry for approximately 30-40 minutes. You do not want the cookies to be browned. Just dry to the touch.
Allow cookies to cool thoroughly on the parchment paper.
Video
Notes
Meringues can be stored at room temperature for 3-4 days.Refrigerate for about 7-10 days.Freeze for longer storage. They should freeze for at least a month.Make sure the egg whites are beaten enough to form stiff peaks. When you pull the whisk out of the egg whites, the peak that forms should hold indefinitely.Use fresh egg whites or previously frozen egg whites that have been thawed.