PREPARATION:

1. Melt unsweetened chocolate in top of double boiler over hot, not boiling, water. Remove from heat; cool. Cream butter and granulated sugar in large bowl until light. Add egg and melted chocolate; beat until fluffy. Stir in cake flour, vanilla and salt until well blended. Cover; refrigerate until firm, about 1 hour.
2. Preheat oven to 400°F. Lightly grease cookie sheets or line with parchment paper. Divide dough into 4 equal parts. Divide each part into 12 pieces. To form pretzels, knead each piece briefly to soften dough. Roll into rope about 6 inches long. Form each rope into pretzel shape on prepared cookie sheet. Repeat with all pieces of dough, spacing cookies 2 inches apart. Bake 7 to 9 minutes or until firm. Remove to wire racks to cool.
3. Prepare Mocha Glaze. Dip pretzels, one at a time, into glaze to coat completely. Place on waxed paper, right side up. Let stand until glaze is set.
4. Melt white chocolate in small bowl over hot water. Squeeze melted chocolate through pastry bag or drizzle over pretzels to decorate. Let stand until white chocolate is completely set.