Combine both flours, baking powder, and salt in a bowl. Melt 1 tablespoon of butter and set aside. In a separate bowl, whisk together the milk, egg, and the melted butter, then whisk into the flour mixture until just combined. Heat 1 tablespoon of butter in a medium saute pan on medium-high heat and drop the batter into the hot skillet, 1 tablespoon at a time (using a tablespoon measure makes this very easy). Cook over medium heat until bubbles form on the top side of the blini, about 2 minutes. Flip and cook for 1 more minute, or until lightly brown. Repeat with the remaining batter adding butter as necessary. Set aside.