The mille-feuille (French pronunciation: [mil fœj], “thousand sheets”), vanilla slice, cream slice, custard slice, also known as the Napoleon, is a pastry originating in France. Traditionally, a mille-feuille is made up of three layers of puff pastry (pâte feuilletée), alternating with two layers of pastry cream (crème pâtissière), but sometimes whipped cream, or jam is substituted. The top pastry layer is dusted with confectioner’s sugar, and sometimes cocoa, or pulverized nuts (e.g. roasted almonds). Alternatively, the top is glazed with icing or fondant in alternating white (icing) and brown (chocolate) stripes, and combed.elebrate black and white glaze will make you feel that you are in the heart of Brooklyn!