1 c. unsalted butter, room temperature
1 c. sugar
1 egg plus 1 egg yolk, room temperature
1 tsp. vanilla
2 2/3 c. flour
3/4 tsp. salt
1/2 c. walnuts, very finely chopped
1/3 c. jam/jelly/preserve/fruit butter/etc.
1. Cream butter using a mixer with a paddle attachment on medium. Add sugar, beat until smooth. Add egg, yolk, vanilla one at a time, mix until incorporated.
2. Combine flour, salt, and ground walnuts in a separate bow and mix. Slowly add to the butter. Mix until dough pulls away from the slide of the bowl. Knead a few times, wrap in plastic and chill 1 hour.
3. Preheat oven to 350. Lightly grease or parchment a cookie sheet.
4. Roll dough into 1″ balls. Place on cookie sheet 2″ apart. Make an indentation in the center of each with your thumb. Fill with a generous 1/4 tsp. of jam.
5. Bake until edges are golden brown, 14-15 minutes. Remove from oven and allow to rest for a minute before transferring to a rack to cool. Top with additional jam if desired.
Makes 3 dozen.