Bake hazelnuts in a shallow pan at 350°, stirring occasionally, 5 to 10 minutes or until toasted.
Microwave morsels and whipping cream in a 2-cup glass measuring cup at HIGH 1 1/2 minutes or until morsels melt, stirring twice. Stir in liqueur. Pour into a wax paper-lined 15- x 10-inch jellyroll pan; freeze 2 hours or until firm to touch.
Shape 1/2 teaspoon chocolate mixture around each hazelnut, coating completely, and place on wax paper.
Microwave white chocolate baking squares in a 1-quart microwave-safe bowl at HIGH 1 1/2 minutes or until melted, stirring twice. Coat plastic candy molds with a thin layer of white chocolate using a small paintbrush; let stand 1 hour or until firm. Place coated hazelnuts in molds; brush with remaining white chocolate, sealing to edges of molds. Let stand at room temperature 1 1/2 hours or until firm.
Invert molds; tap firmly on cutting board to remove candy.
Microwave coating in a 1-cup glass measuring cup 1 minute or until melted, stirring once. Pour into a small heavy-duty zip-top plastic bag; seal. Snip a tiny hole in 1 corner of bag; drizzle over truffles. Let stand until firm.