Sift flour in a separate bowl
Cream butter with brown sugar until fluffy & ligh in a medium sized bowl
Beat in Egg Yolks and Vanilla Extract
Stir in flour half at a time, blending well to make stiff dough
In a pie plate beat egg whites until foamy
Sprinkle nuts on waxed paper or paper plate
Take a teaspoonful of dough and roll into balls between the palms of hands
Roll each ball in the egg whites and then into the nuts coating entirely (if no nuts still roll in egg white)
Place 2 inches apart on cookie sheet and press a hollow in the center of each with fingertip
Bake in moderate oven at 350 degrees for 12 minutes or until firm & lightly golden
Remove from cookie sheets to a wire cooling rack
Cool completely and place a fondant egg in each nest