Thumbprints - cooking recipe

Ingredients

2/3 c. butter
1/3 c. sugar
2 egg yolks
1 tsp. vanilla
1 1/2 c. plain flour
2 slightly beaten egg whites
3/4 c. finely chopped pecans or walnuts
1/3 c. strawberry preserves
1/2 tsp. salt

Preparation

Cream butter and sugar until fluffy.
Add egg yolks, 1/2 teaspoon salt and vanilla.
Beat well.
Gradually add flour; mix well.
Shape into 3/4-inch balls, dip in egg whites and roll in nuts.
Place 1-inch apart on greased cookie sheet.
Press down centers with thumb; make a small well in each.
Bake at 350\u00b0 for 15 minutes.
Cool and remove from pan.
Fill centers with preserves.