MIX flour, baking soda and salt. Microwave chocolate and butter in large microwaveable bowl on HIGH 2 min.; stir until chocolate is completely melted. Add cream cheese; stir until completely melted. Stir in 1 cup sugar, egg and vanilla. Add flour mixture; mix well. Refrigerate 15 min.
HEAT oven to 375°F. Roll dough into 1-inch balls; coat with remaining sugar. Place, 2 inches apart, on baking sheets. Press your thumb into center of each ball; fill each indentation with about 1/4 tsp. jam.
BAKE 8 to 10 min. or until lightly browned. Cool 1 min. on baking sheets; transfer to wire racks. Cool completely.