For the yeast starter: In a large bowl combine flour, sugar and 1 packet of yeast. Set aside. Make the “yeast starter” by heating the milk and the water to 100 degrees F. Whisk the warm milk mixture into the dry ingredients until combined. Cover with plastic wrap and leave at room temperature for one hour.
For the pancake: Pre-heat oven to 400 degrees F. In a small saucepan, melt 4 tablespoons butter. In a small bowl, whisk eggs. Set aside. Whisk remaining flour, a little at a time, into the yeast mixture followed by the sugar, baking soda and salt. Set aside. Add melted butter to eggs, then whisk into flour/yeast mixture to finish the batter.
Place a dry cast iron skillet over medium/high heat. Cut bacon into “lardons” or chunks. Add to pan. Cook until bacon is halfway done and fat begins to render. Meanwhile, remove sausage from their casings and break into large chunks. Add to bacon and continue cooking until everything is crispy and fully cooked. Drain off some of the fat leaving enough to coat the bottom of the pan. Using a spatula, pour the batter into the skillet. Bake 10 minutes, checking after 8 minutes.
Pancake will be done when batter is set and solid all the way through. Immediately after the pancake is cooked, spread remaining two tablespoons butter on top, followed by the maple syrup. Finish with a sprinkle of powdered sugar.