Stir the yeast into the warm water. Stir until dissolved. Add mashed potatoes and flour. Stir all other remaining ingredients into bowl. Knead by hand for approximately 5 minutes, or until dough is elastic and smooth. Place dough in a mixing bowl sprayed with nonstick spray. Set in a warm area, covered with a towel, and let rise for 1 hour. Punch down dough and divide into two halves. On a lightly floured surface, roll dough out until it is very thin. The shape of the pizza doesn?t really matter ? round or square. The idea is for it to be homestyle, not perfect. Preheat oven to 400°. Place dough on baking sheet or pizza sheet. Top with desired amount of pizza sauce, spreading evenly. Evenly distribute the cheese and your favorite toppings. Bake for 17 to 21 minutes, or until crust edges become light brown. When pizza is done, take out of oven and let rest for 3 minutes. Slice and serve.