Assemble the grain mill and attach to the mixer. Set the mill on the finest setting and then turn the knob back two notches. Turn the mixer to speed ten and grind corn into the mixer bowl placed under the mill. Repeat with wheat berries after setting the mill on the finest setting and turning the knob back one notch. Add baking powder and salt to the mixer bowl; mix well. Add all remaining ingredients. Attach the bowl and flat beater to the mixer. Turn the mixer to Stir speed and mix about 15 seconds.
Stop and scrape the bowl. Turn the mixer to Stir speed and mix about 15 seconds. Spoon the batter into greased muffin pans. (Do not use cupcake liners. ) Bake at 400 degree Fahrenheit (204 degree Celsius) for 15 to 18 minutes, or until toothpick inserted into center comes out clean. Remove from pans immediately. Serve warm.