Sift flour, baking powder, baking soda and cinnamon in a large bowl.
Place the eggs in another bowl and whisk briefly, then add the skim milk, cider vinegar, canola oil and pureed pumpkin and stir.
Add the wet ingredients to the dry ingredients and stir with a spoon just until combined----Do not over mix, it will make the pancakes tough.
Add the walnuts and briefly stir again.
Pour the batter in a batter dispenser (pictured below) and let it sit, without stirring, for 10 minutes.
Preheat a large nonstick skillet or griddle for 3-4 minutes so that it's nice and hot.
Pour the batter on the preheated pan (or onto the griddle) by pulling the release handle to make perfect circles.
Cook until the edges are dry and you see some bubbles on the surface, 2 to 3 minutes.
Flip and cook until golden brown on the other side, 30-40 seconds more.