Butter and coffee essence by Cake and Cookie recipes on April 13th, 2012 · without comments Lumps of butter on a plate with a knife and coffee essence in an eggcup with a teaspoon. Both are ingredients in making the Coffee Mousseline used as the filling and topping for Coffee and Walnut Cake.Share: Share on Facebook Share on Twitter Share on Google+ Share on LinkedIn™ Share on Pinterest Coffee and Walnut Cake Recipe Leave a Reply Click here to cancel reply. Name (required) Mail (will not be published) (required) Website