1. Combine dry ingredients and nut in a large bowl. Toss to mix.
2. In a separate bowl, beat the eggs until frothy, then whisk in 1 1/3 cups of the milk, the sour cream, maple syrup, butter, and a banana. Add additional milk, a tablespoon at a time, to thin batter, if needed. Make a well in the dry ingredients, then pour in the egg mixture. Stir, just to blend; do not beat. Let the batter stand for several minutes.
3. Heat a large skillet over medium-high heat, then butter lightly. Drop the batter by heaping tablespoonfuls and cook until golden and bubbles form on surface (1 minute), turn and cook on other side.
4. Serve with maple syrup