Cream butter using a mixer fitted with a paddle attachment on medium speed. Add sugar and beat until smooth. Add egg, egg yolk and vanilla essence, one at a time. Mux until incorporated.

Combine flour, salt and ground walnuts in a separate bowl and whisk until uniform. Slowly add flour mixture to the butter. Mix until dough pulls away from side of the bowl. Knead a few times and chill dough for 1 hour.

Preheat oven to 350 ºf and lightly grease a cookie sheet.

Roll dough into 1 inch balls. Place on prepared cookie sheet 2 inches apart. Make an indentation In the center of each ball and fill with 1/4th teaspoon of jam.

Bake for 14 to 15 minutes. Remove from oven and cool. Serve with coffee or tea