Melt the butter.

Add sugar and milk. Simmer, stirring constantly until the sugar disolves. Then let the mixture cool down for about 15min.

Add the milk powder slowly to the cooled down mixture, stirring constantly. Continue stirring and add the cocoa powder.

When still hot, equally distribute the mixture across all but one wafles.

Put the wafles on top of each other with the chocolate mixture facing up. Place the remaining wafle on top of it.