1/2 c. (1 stick) butter
1/4 c. firmly packed light brown sugar
1 egg yolk (from a lg. egg)
1/2 tsp. vanilla
1 c. fork-stirred all-purpose flour
About 1/2 c. finely chopped (rice-grain size) unblanched or blanched almonds, filberts, pecans, or walnuts
Thick homemade or commercial strawberry preserves or imported ginger marmalade

In a medium mixing bowl, thoroughly beat together the butter, sugar, egg yolk and vanilla. With a spoon, gradually stir in the flour until smooth. Cover tightly and chill until firm enough to handle. Work with half of the dough at a time, keeping remaining portion chilled.

Using 1 tablespoon for each, shape dough into balls; roll in nuts. Place about an inch apart on ungreased cookie sheets; gently press a thumb into the center of each ball to make a shallow indentation; fill indentations with preserves, about 1/2 teaspoon for each.

Bake in a preheated 350 degree oven until lightly browned, about 12 to 15 minutes. With a wide metal spatula remove to wire racks to cool. Store in a tightly covered container. Makes about 1 1/2 dozen.