Heat oven to 350°F. In large microwavable bowl, microwave baking chocolate and butter uncovered on Medium (50%) 2 to 3 minutes, stirring once, until softened. Stir in condensed milk, liqueur, flour and hazelnuts. Cover and refrigerate until firm, about 30 minutes.
Shape dough by tablespoonfuls around each chocolate star. On ungreased cookie sheet, place 1 inch apart.
Bake 7 to 8 minutes or until dough is shiny and set but still soft. Cool 5 minutes; remove from cookie sheet to cooling rack. Cool about 30 minutes.
In small microwavable bowl, microwave white vanilla baking chips and oil uncovered on Medium (50%) 1 minute to 1 minute 15 seconds, stirring once, until softened. Stir until smooth. Dip top of each cookie into melted mixture; immediately top each with candy sprinkles while mixture is still soft. Let stand until coating is set.