In a medium bowl beat butter medium speed for about 30 seconds. Add the granulated sugar and vanilla extract. Beat until well combined. Beat in as much flour as you can with electric mixer and then using a wooden spoon stir in any remaining flour. Cover and chill for 1 hour or until dough is easy to handle.
Preheat oven to 350 degrees. Shape dough into 1-inch balls. Place balls 2 inches apart on ungreased cookie sheets. Using your thumb, press an indentation into the center of each ball. Spoon about 1/2 teaspoon of the jam into each indentation and then sprinkle with sugar. Bake about 10 minutes or until edges are light brown. Cool on cookie sheets for 1 minute. Transfer cookies to wire racks to finish cooling.