Combine the powdered milk, 1 tablespoon of sugar, the salt, shortening, and hot water in a medium bowl. Stir until the sugar and salt are dissolved and set aside to cool while the yeast proofs.
In a small bowl, add the yeast and 1/8 teaspoon of sugar to 1/3 cup of warm water and rest until yeast has dissolved. Add this to the powdered milk mixture. Add the sifted flour and beat thoroughly with a wooden spoon. Cover the bowl and let it rest in a warm spot for 30 minutes.
Heat an electric griddle to 300ºF.
Situate 4 (3-inch) metal rings onto the griddle and coat lightly with vegetable spray. Lightly sprinkle the insides of the rings with cornmeal. Scoop batter into each ring and cover with a half-sheet pan. Cook for 5 to 6 minutes. Remove the sheet pan and flip the rings using tongs. Cover with the lid and cook until golden brown, another 5 to 6 minutes. Place on a wire rack, remove rings, and cool. Repeat with remaining batter. Split with a fork and serve.