For the dough, heat the milk, vegetable oil and sugar in a large saucepan over medium heat; do not boil. Set aside to cool to lukewarm. Sprinkle the yeast on top and let it sit on the milk for 1 minute.
Add 8 cups of the flour. Stir until just combined, cover with a clean kitchen towel and set aside in a relatively warm place for 1 hour.
Remove the towel and add the baking powder, baking soda, salt and the remaining 1 cup flour. Stir thoroughly to combine. Use the dough right away or place in a mixing bowl and refrigerate for up to 3 days, punching down the dough if it rises to the top of the bowl.
Remove half of the dough. On a floured surface, roll out the dough into a large rectangle, about 30 by 10 inches, with a long side facing you.
To make the filling, pour 1 cup of the melted butter over the surface of the dough. Use your fingers to spread the butter evenly. Generously sprinkle half of the ground cinnamon and 1 cup of the sugar over the butter. Don't be afraid to drizzle on more butter or more sugar!
Beginning at the end farthest from you, roll the rectangle tightly toward you. Use both hands and work slowly, being careful to keep the roll tight. Don't worry if the filling oozes as you work; that just means the rolls will be divine. When you reach the end, pinch the seam together.
Transfer to a cutting board and, with a sharp knife, make 1 1/2-inch slices. One log will produce 20 to 25 rolls. Pour a couple of tablespoons of melted butter into several pie pans or baking dishes and swirl to coat. Place the rolls in the pans cut-side up, being careful not to overcrowd.
Repeat the rolling-sugar-butter process with the other half of the dough and more pans. Preheat the oven to 375 degrees F. Cover each pan with a kitchen towel and let rise on the countertop for at least 20 minutes before baking. Remove the towels and bake for 13 to 17 minutes, until golden brown. Don't allow the rolls to become overly brown.
While the rolls are baking, make the icing: In a large bowl, whisk together the confectioners' sugar, milk, butter, coffee and salt. Splash in the maple flavoring. Whisk until very smooth. Taste and add more sugar, butter or other ingredients as needed until the icing reaches the desired consistency. The icing should be thick but still pourable.
While the rolls are still warm, generously drizzle icing over the top. Be sure to get it all around the edges and over the top. As they sit, the rolls will absorb some of the icing's moisture and flavor. They only get better with time...not that they last for more than a few seconds!