Heat oven to 350°F and line a cookie sheet (with sides) with parchment paper (you can also split the batter between two 8" square pans and one 9x13" pan - they are thin layers, OR 4 8" pans OR 2 9x13" pans ).
In a big stainless steel bowl, melt butter and dark chocolate in the microwave (yes, you read it right…microwave…as long as it is stainless steel, it can go in the microwave). Heat for 2 minutes on high and stir until all is melted and smooth.
In another bowl, combine eggs, coffee, vanilla and sugar. Whisk vigorously until combined. Add to chocolate and butter mixture and whisk again….it should be oh soooo chocolatey! In a small bowl, combine flour, baking powder and salt; add chocolate chips and add to chocolate mixture…blend again.
Pour into pan (or pans) and smooth out. Sprinkle walnut over top and bake in oven for 30 minutes (don’t overcook or you will lose the fudgy goodness!). Remove from oven.
Make Rice Krispy layer: place chocolate chips and creamy peanut butter in a large microwave-safe bowl. Microwave in 30-second intervals until melted; stir until smooth. Stir in Rice Krispies; spread over the brownie layer.
To make the chocolate layer, in a small bowl, melt the chocolate chips (2 cups) and coconut oil in the microwave until melted; pour evenly over rice krispy layer among the pans. Refrigerate, covered, at least 30 minutes or until set.
Cut into bars and serve.