HEAT oven to 350ºF.

LINE 8x4 inch loaf pan with parchment paper or foil. Microwave chocolate and butter in small microwaveable bowl on HIGH 1 min. or until butter is melted; stir until chocolate is completely melted.

BEAT eggs and sugar in medium bowl with whisk until well blended. Stir in coffee, zest and chocolate mixture. Add flour; mix well. Stir in nuts. Pour into prepared pan.

BAKE 30 to 35 min. or until toothpick inserted in centre comes out with fudgy crumbs. Cool in pan 10 min. Remove to wire rack; cool completely. Use a serrated knife to carefully cut width-wise into 10 slices.