Preheat oven to 350 degrees. In a bowl, combine sugar and butter and cream well. Add flour and mix well. Shape dough into 1-inch balls and place on cookie sheets. Make a dent in each cookie using your thumb and place a spoonful of red raspberry jam in each dent.
Bake for 15 to 20 minutes in preheated oven. Cool completely on wire racks. Enjoy!