Sift the flour and cocoa powder to remove lumps then mix well. Set aside.
Prepare non-stick pan over low heat.
Pour just 1 cup of evaporated milk first into the pan. Then add sugar, butter, vanilla extract, and coffee powder. Mix and cook until the butter is completely dissolved.
Add the mixed flour and cocoa powder. Mix continuously. After a few minutes, gradually add the other 1 cup of evaporated milk. Mix continuously. If the mixture can hold a shape then it is done.
Transfer the brownies mixture into a container with aluminum foil or wax paper. Flatten the surface using a spoon or spatula. Set aside.
For making the frosting, a double boiler is needed but you can improvise. A pot with boiling water at the bottom and a non-stick pan on top will do.
Pour 1/4 cup of evaporated milk into the boiler. Add the dark chocolate pieces. Continuously mix and cook until the chocolate melts.
Pour the frosting evenly on top of the brownies mixture. Sprinkle with chopped peanuts or you can also use choco chips or mini marshmallows if you want.
Chill overnight in the refrigerator.
Slice into bite-sized bars before serving. Enjoy your no bake brownies!