1 Preheat oven to 300°F. Beat butter and sugar in large bowl with electric mixer on high speed until light and fluffy. Add egg yolk; beat well. Add flour and cinnamon; beat on low speed until well blended. Press dough evenly into a 1/4-inch thick rectangle on large (at least 15x12-inch) ungreased baking sheet.
2 Beat egg white until foamy. Brush on dough. Sprinkle with nuts, pressing nuts lightly into dough.
3 Bake 45 minutes or until lightly browned. While still hot, cut into 36 bars, 2 1/2x1 1/2-inch each. Remove from baking sheet. Cool completely on wire rack.
4 Melt chocolate chips in separate bowls as directed on package. Spoon each melted chocolate into a small resealable plastic bag. Cut a small piece from one of the bottom corners of each bag. Close bags tightly, then drizzle the chocolates in a decorative pattern over the bars. Let stand until chocolate is set. Store in an airtight container.