Preheat oven to 350 degrees F. Lightly grease a 13×9 baking dish. Line the pan with parchment paper so that paper is along bottom and up the two longer sides and goes a little above top of pan sides. Then lightly grease the parchment paper.
Place butter, 1 bag of chocolate chips, and coffee in top of double boiler over medium heat. Stirring occasionally, heat mixture until smooth (about 5-7 minutes). Remove from heat and set mixture aside to cool. [OR you can place ingredients in microwave safe bowl and microwave on high for 30 second intervals, stirring after each interval, until smooth.]
Whisk together eggs, sugar, and vanilla until well combined in a large mixing bowl.
In a separate small mixing bowl, stir together flour, baking powder, and salt. Whisk cooled chocolate mixture into sugar/egg mixture, then stir in flour mixture until just combined.
Pour about half of brownie mixture into bottom of prepared 13×9-inch baking dish. Spread batter to cover bottom of pan into an even layer. Bake at 350 degrees F for 10 minutes.
Meanwhile, place peanut butter chips in medium mixing bowl, set aside. Place cream in small sauce pan over medium heat. Stir until it just starts to bubble. Remove from heat, and pour over peanut butter chips. Stir until smooth. [OR you can place chips and cream in microwave safe bowl and microwave on high for 30 second intervals, stirring after each interval, until smooth.] Set aside to cool.
When bottom brownie layer is done, remove from oven. (don’t worry if it’s not fully cooked), pour cooled peanut butter ganache over brownie layer. Sprinkle nuts then remaining 1 bag of chocolate chips on top. Spoon remaining brownie batter on top and gently spread batter over chocolate chips to edges of pan to cover filling.
Bake brownies an additional 25-30 minutes at 350 degrees F or until almost set in middle. Brownies may appear slightly underdone, but that’s ok. Be careful to not overbake and dry out brownies.
Cool completely. For easy cutting, place brownies in fridge for several hours over overnight to firm. Gently lift on parchment paper to remove brownies from pan and remove paper. You may need to run a sharp knife around edge of pan to remove brownies. Cut brownies into squares. For a firmer fudgier brownie, store in fridge. Otherwise, store at room temperature for a few days.
SNAPPY TIPS: Be sure melted chocolate mixture and peanut butter ganache are cool before adding to recipe.SNAPPY SUBSTITUTIONS: You can substitute other types of chocolate for the dark chocolate, however, I suggest sticking with a chocolate that is not too sweet.