In a large mixing bowl, combine Bisquick, eggs, milk, and bananas. Using a wire whisk, beat until batter is somewhat smooth but has a few lumps from the bananas. Add the peanut butter and walnuts and beat well.
On a heated griddle or non-stick skillet, spray non-stick cooking spray. Pour just under 1/4 cup of the batter into the skillet. If using a large skillet, you should be able to get 3 to 4 pancakes per batch. Don't overcrowd the skillet.
Cook until edges are dry and batter starts to bubble a little in the middle. Carefully turn the pancake over using a spatula. Once you have flipped the pancake, take a basting brush and dip into butter. Carefully spread the butter over the pancakes while they are in the skillet.
You can also put layers of sliced bananas between the pancakes and drizzle with a little warm honey.
Serve with sliced bananas, walnuts and warm honey or maple syrup on top.