Preheat oven to 400 degrees. Lightly oil a 6 cup standard muffin tin, or use paper liners. In a medium bowl, combine cereal and milk; let stand until softened, about 5 minutes. In a small bowl, whisk together flours baking powder, cinnamon, and salt.
Stir oil, egg, and sugar into cereal mixture. Fold in flour mixture. Divide batter among cups. Bake until a toothpick inserted in the center of a muffin comes out clean, 20 to 25 minutes. Cool in tin 5 minutes, then turn out onto a wire rack; let cool completely, or serve warm. Store up to 5 days at room temperature in a resealable plastic bag.