Self-Sufficiency Brownies

In our quest to live without money, we're always trying to find alternatives to things that we can't grow here.  We can't grow wheat.  One day, in the grocery store, I came across a package of potato flour and noticed a recipe for sponge cake made with it.  That got me thinking about using potatoes -- something easily grown here -- as a substitute for wheat flour.  I looked for instructions on making potato flour, with no success.  The one procedure I found was obviously written by someone who had never tried it.  The potatoes turned black and disgusting.  I gave up.

Last night, I heard a forecast of the price of wheat flour, and it made me start thinking again about potatoes.  This morning, I tried something.  I just used mashed potatoes instead of flour in a brownie recipe.  The brownies turned out fine.  The potato taste doesn't come through at all.  I'm going to experiment some more.  In the meantime, here's the recipe I used:

    4 heaping tbsp cocoa
    1/2 lb butter
    1 1/2 cup sugar
    4 eggs
    1 cup mashed potatoes
    1 cup chopped nuts (optional)
    2 tbsp espresso powder (optional)

    Melt butter, stir in cocoa, stir in sugar.  Beat eggs, one at a time, into mixture.  Beat in potatoes
    and coffee.  Stir in nuts.  Bake 45 min. in oiled 9"x13" pan.  Cool in pan.

I'd still like to find out about making potato flour at home.