1. Heat oven to 350°F.
2. Beat butter and brown sugar in large bowl until well blended. Add egg, vanilla and instant coffee, if desired; beat until fluffy. Stir together oats, flour, baking soda, salt and 1/2 cup walnuts; gradually stir into butter mixture with spoon. (Dough will be thick.) Set aside 1 cup dough.
3. Press remaining dough evenly onto bottom of ungreased 13x9x2-inch baking pan. Spread chocolate spread evenly over dough. Crumble reserved dough evenly over filling. Sprinkle with remaining 1/4 cup walnuts.
4. Bake 20 to 25 minutes or until top is golden brown (chocolate will be soft). Cool completely in pan on wire rack; cut into bars. Makes about 24 bars.