Preparation time: 15-20 minutes
Cooking time: few minutes
Cooling time: 1 hour + 1 hour

Bottom layer

1. Grease a 23 cm / 9-inch square cake pan.
2. Combine butter, sugar, cocoa, egg, and cardamon in a heavy sauce pan. Heat over low heat, stirring constantly, until mixture thickens.
3. Add graham crackers crumbs, coconut, and chopped walnuts, stirring to combine. Press the mixture in the greased pan.

Middle layer

1. Beat together butter, confectioners' sugar, vanilla custard or pudding powder, acream and coffee, until the mixture is creamy.
2. Spread over graham cracker base in cake pan. Refrigerate bars until firm, at least 1 hour.

Topping

1. Melt semi-sweet chocolate and 1 Tablespoon butter. Drizzle over chilled bars. Return to refrigerator to chill until firm (at least 1 hour).
2. Cut into squares and serve.