Heat oven to 350°F. In medium bowl, stir walnuts, sugar and butter until moistened. Press mixture evenly on bottom of ungreased 13x9-inch pan or 12x8-inch (2-quart) glass baking dish. Bake 8 to 15 minutes or until edges are just golden brown. Cool 30 minutes.
In large bowl, knead cookie dough and espresso granules until blended. Drop small spoonfuls of dough evenly over walnut crust. Gently press dough together evenly over crust. (If dough is sticky, use floured fingers.)
Bake 20 to 25 minutes or until golden brown. Cool 30 minutes.
In medium microwavable bowl, microwave baking chips and whipping cream uncovered on High 1 minute, stirring after 30 seconds; stir until chips are melted and mixture is smooth. Spread chocolate mixture over bars. Refrigerate 1 hour. For bars, cut into 6 rows by 4 rows. Cover and refrigerate any remaining bars.