Chill until serving time. Bring the water to a boil, reduce heat to low and cook until chocolate and butter melt. Remove from heat, stir in egg yolks one at a time, beating well each time with a wooden spoon. Stir in brandy and sugar and beat well. Beat egg whites until stiff but not dry and gently fold into chocolate mixture.
Spoon mousse into stemmed glasses and refrigerate.
Top with whipped cream before serving. Add egg, beating well. Combine dry ingredients and add to creamed mixture, beating well. Shape dough into 1-inch balls. Place 2 inches apart on greased cookie sheets.