Light and Fluffy Buckwheat Pancakes with Blueberry Sauce

Mix the pancake batter
0 Put the flours, sugar, baking powder, salt, baking soda and lemon zest in a large bowl and whisk to combine.
1 Crack the eggs into a medium bowl and whisk briefly. Stir in the buttermilk, milk and oil and whisk until smooth.
2 Make a well in the bowl with dry ingredients and pour in the buttermilk mixture. Mix until well blended and all bits of flour are incorporated.
3 Heat a heavy skillet or griddle over medium-high heat, or heat an electric griddle to 350 (175C) degrees. Lightly oil the surface of the pan with oil. 
8 Ladle ¼ cup batter onto the griddle. Cook 1½-2 minutes, or until the edges of the pancakes look golden, and the batter forms bubbles that pop and stay open on the surface. Nudge a spatula around the edges of the pancake to loosen, then flip them over and cook the second side for about another minute. 
9 Continue making pancakes until the batter is gone. (To keep the cooked pancakes warm, transfer them to a baking sheet in a 225 degree oven).
Make the blueberry sauce
4 Put blueberries and maple syrup in a small saucepan over medium-low heat. Cook until the blueberries begin to burst and release their juice.  Remove from the heat and stir in the butter. 
5 Serve the warm pancakes topped with the blueberry sauce and additional maple syrup on the side.