Make the brownie cake by whipping the egg whites in a large bowl (not plastic)
with an electric mixer until they become thick.
Add the sugar to the egg whites and continue beating until the mixture
forms soft peaks.
To the egg white and sugar mixture, add the shortening, chocolate syrup,
fudge topping, water, and vanilla.
In a separate bowl, combine the flour, cocoa, salt, and baking soda.
While beating the wet mixture, slowly add the dry mixture and mix until
smooth.
Lightly grease a 9" pie pan with shortening. Pour the brownie batter into
the pan and sprinkle the chopped walnuts over the top. Bake for 35 minutes
or until a toothpick poked into the center comes out clean.
When the brownie pie has cooled a bit, slice it into 9 equal pie-shaped
portions.
Arrange a slice of the low-fat brownie pie on a plate next to a scoop of
vanilla frozen yogurt.
Drizzle the warmed chocolate sauce over the top of the brownie and frozen
yogurt, and serve.