In a medium-size bowl sift together flour, baking powder,
baking soda, granulated sugar and cocoa powder.
In a large bowl beat together egg yolks, milk, sour cream and vanilla.
Gradually stir in flour mixture and melted chocolate and butter.
Beat until smooth. Stir in walnuts.
In a small bowl whip egg whites until soft peaks are formed.
Fold into batter. Batter will be thick.
Lightly brush hot grids with shortening or oil.
Pour enough batter to fill two-thirds of the waffle iron.
Push batter out to the edges with a wooden spoon.
Cook until crisp and a dark rich brown.
Be careful not to overcook.
Keep finished waffles warm in the oven on a rack
until ready to serve. Repeat with the remaining batter.

To serve cut waffles into quarter sections.
Sprinkle powdered sugar through a fine sieve over the top.
Makes about 3 waffles or 4 servings.

Serve with powdered sugar or with ice cream,
Chocolate Fudge Sauce and whipped cream.