In a 4-cup glass measuring cup, whisk together the soy milk, bananas, ground flaxseeds, and vinegar.
Refrigerate the mixture for five minutes: this gives the flaxseeds a chance to gel slightly and the soy milk to curdle. Whisk in the oil.
In a mixing bowl, combine the oat, buckwheat, and coconut flour along with the coconut sugar, baking powder, cinnamon, nutmeg, and salt.
Fold in the soy milk mixture and the walnuts. Mix only enough to eliminate any large lumps or dry spots; make sure not to over mix.
Preheat a seasoned griddle over medium heat.
Lightly oil the griddle and for each pancake, spoon 1/4 cup of batter, taking care not to overcrowd the griddle.
Bake for about two minutes or until the edges begin to look dry. Carefully flip only once and bake until pancakes are firm to the touch; take care when flipping, as gluten-free pancakes are a little more fragile than wheat pancakes.
Serve hot with toppings such as banana slices, chopped walnuts, vegan butter, maple syrup, or ground cinnamon.