Preheat oven to 160 degrees. Grease a 9x13 inch pan and set aside.
In a saucepan, melt butter, chocolate, cream and coffee powder. Allow to cool completely.
In a mixing bowl, whisk eggs, sugar, salt and vanilla till fluffy and creamy.
Pour the chocolate mixture and beat till combined.
Sift the cocoa powder, flour and salt into the mixture. Add the chocolate chips and walnuts. Fold till just combined.
Pour into the prepared pan. Crush salt on top (highly recommended!) and/or nuts and chocolate or choice.
Bake for 50 minutes. Allow to cool for 20 minutes. Dig in!
