In a large bowl, cream butter and sugar until light and fluffy. Add the egg, chocolate and vanilla; mix well. Combine flour and salt; gradually add to creamed mixture and mix well. Cover and refrigerate for 1 hour or until firm.
Divide dough into fourths; form each portion into a 6-in. roll. Cut each roll into 1/2-in. slices; roll each into a 9-in. rope. Place ropes on greased baking sheets; form into pretzel shapes and space 2 in. apart. Bake at 400° for 5-7 minutes or until firm. Cool 1 minute before removing to wire racks to cool completely.
For glaze, in a microwave-safe bowl, melt the chocolate chips, shortening and corn syrup; stir until smooth. Stir in confectioners' sugar and enough coffee to make a smooth glaze.
Dip pretzels; allow excess to drip off. Place on waxed paper until set. Melt white chocolate. Drizzle with white chocolate; allow excess to drip off. Let stand until chocolate is completely set. Store in an airtight container. Yield: 4 dozen.