Sift together the flour, sugar, baking powder and salt in a large bowl. Combine the pumpkin, milk, egg yolks, orange juice and zest in another bowl, mixing until homogenous. Make a well in the dry ingredients. Pour the wet ingredients into the well and mix until combined.
Preheat the griddle.
Beat the egg whites with a pinch salt in a separate bowl, using a whisk or electric mixer, until the whites form stiff peaks. Fold the egg whites into the batter in thirds. Do this quickly and gently, so the pancakes will be light and fluffy.
Melt small pats of butter onto the griddle, and then spread them around with a paper towel to remove any excess. Spoon or ladle the batter onto the griddle to the desired size of the pancake. When the top of the pancakes are full of holes (look like bubbles have risen to the surface and burst), flip and cook until the bottoms are golden brown.
Transfer the pancakes to serving plates, dust with powdered sugar and serve with Cinnamon Maple Syrup, Vanilla Whipped Cream and Thick-Cut Bacon on the side.
Cinnamon Maple Syrup:
Heat the maple syrup with the cinnamon stick in a small saucepan over medium heat. When the syrup is hot, remove from the heat and allow the flavors to steep, about 30 minutes. Yield: 1 cup.
Vanilla Whipped Cream:
Beat the cream and vanilla in a mixing bowl, using a whisk or hand beater, until the cream starts to thicken. Sprinkle in the sugar and beat until the cream is very light and fluffy and holds soft peaks. Yield: 3 cups.
Place the bacon in a medium saute pan over medium heat. Cook until the fat starts to render out and the bacon turns golden brown and crispy, 4 to 6 minutes. Transfer the bacon to a paper-towel-lined plate to drain.