Preheat the oven to 400 degrees F. In the bowl of an electric mixer fitted with a paddle attachment, combine the flours, oats, baking powder, sugar and salt. Blend the cold butter in at the lowest speed and mix until the butter is in pea-size pieces. Combine the buttermilk, maple syrup and eggs and add quickly to the flour-and-butter mixture. Mix until just blended. The dough may be sticky.