Thumbprint Cookies with Jam

Ingredients

• 1 1/2 cups all-purpose flour
• 1/2 teaspoon salt
• 1 stick (1/4 cup) unsalted butter, softened
• 1/2 cup sugar
• 1 large egg yolk
• 1 teaspoon pure vanilla extract
• 1/4 cup seedless raspberry jam , apricot preserves or strawberry preserves

Directions

• TO MAKE DOUGH:
  
  Whisk together flour and salt. Beat butter and sugar with an electric mixer until very pale and fluffy, about 4 minutes, then beat in egg and vanilla. At low speed, mix in flour mixture just until a dough forms. Form into a 6-inch disk, then chill, wrapped in plastic wrap, until firm, about 1 hour.
• TO ASSEMBLE AND BAKE COOKIES:
  
  Preheat oven to 350°F with rack in middle. Line 1 large baking sheet with parchment paper.
• Roll a level teaspoon of dough into a ball, then flatten each ball slightly (to 1 inch wide and 1/2 inch thick). Make a deep indentation in center of each round with your thumb or wooden spoon handle. Make more cookies, arranging them 1 inch apart on baking sheets.
• Fill indentations in each cookie with about 1/8 teaspoon jam, avoiding any large pieces of fruit.
• Bake until cookies are baked through and golden-brown on edges, 10 to 12 minutes. Cool on baking sheets 1 minute, then transfer to racks to cool completely.
• by-http://www.kitchendaily.com/cookie-recipes/cooking-with-kids/