Moosewood Fudge Brownies

• 5 eggs
• 1 ripe banana
• 1 semisweet choc chips
• 3/4 fudgier ones
• 375 gr brown sugar (light)
• 220 gr butter
• 160 gr unsweetened chocolate
• 130 gr flour
• 120 gr walnuts (chopped)
• 20 gr strong black coffee