Lightly butter inside of a 10-inch, 12-cup Bundt pan. Sprinkle with flour and shake out excess.
In a mixing bowl combine the ginger, raisins and walnuts.
Sift together 3 cups flour, baking powder, and salt. Sift this mixture over ginger-and-nut mixture.
Put 1 pound butter into the bowl of an electric mixer. Start beating while gradually the sugar. Cream mixture well and gradually beat in yolks. Beat.
in 1/3 cup Madeira.
Pour and scrape this mixture over nut mixture, and blend the ingredients thoroughly. This is best done by hand.
Beat egg whites until stiff, and fold into the batter thoroughly, until they do not show.
Pour the batter into the prepared pan and smooth over top with spatula. Set pan on baking sheet and place in oven. Bake about 2 1/4 hours, or until cake is puffed above pan and nicely browned on top, or until internal temperature is 200 degrees F. on thermometer.
Remove from pan shortly after baking. Tapping bottom of pan with heavy knife will help. Store cake for at least 10 days. If desired, add occasional touch or more of Madeira, dry Sherry, Cognac or rum. Keep closely covered, wrapped in cheesecloth and foil, and refrigerated until ready to use.