Beat butter, sugar, yolks and almond extract in bowl until fluffy and light. Stir in flour, blending well. Wrap in plastic wrap; refrigerate overnight.
Heat oven to 350°F. Roll dough, one teaspoonful at a time, into balls slightly less than 1 inch. Roll each on lightly floured surface to 9-inch length. Form into pretzel shape and place on ungreased baking sheet. Repeat, spacing 2 inches apart.
Bake at 350°F for 10 minutes or until firm-cookies will be pale. Cool on sheet on wire rack; remove to rack to cool completely.
Beat egg whites and water as directed on package until foamy. Beat in sugar and cocoa powder and beat at high speed until smooth. Dip cooled cookies in icing; place right side up on rack over waxed paper to catch drips. Sprinkle with nonpareils.