In a small saucepan, warm water over medium-low heat until it reaches 110°F on an instant-read thermometer. Transfer water to a medium bowl. Whisk in the yeast and 17 grams of molasses until both are dissolved. Allow the mixture to sit until it’s foamy on top, about 5 minutes.
Whisk together flour and salt in a stand mixer bowl. Fit stand mixer with the dough hook attachment. Combine the yeast mixture with the flour on low speed, just until a shaggy dough forms. Scrape down the sides and increase speed to medium as needed until the majority of the loose flour is incorporated into the dough. Once a shaggy dough is formed, increase the speed to medium high and set a timer for 10 minutes to allow the dough to knead. During this time, keep an eye on your stand mixer to ensure it doesn’t wiggle off the counter or overheat. If at any time your mixer becomes too hot, take a break or begin hand kneading (see notes). You know your dough is done kneading when it is flexible and bouncy to the touch. To be extra safe, grab a piece of dough between your fingers, stretch it, and see the web fibers that have developed. You should be able to pull the dough thin enough that light shines through. If your dough rips as soon as you start pulling, you need to keep kneading the dough. You want the dough to be able to stretch rather than tear.
Turn oven to 200°F. Place the dough in a clean bowl and cover with plastic wrap. Allow the dough to rise on top of the warm oven (not in the oven) for 60 - 90 minutes until it’s nearly doubled in size.
While the dough is rising, prepare two baking sheets generously sprinkled with cornmeal. Set aside.
Punch down the risen dough a few times to release some of the gas that formed. On a clean, unfloured surface, remove the dough from the bowl. Using a bench scraper, divide the dough into pieces weighing about 113g each.
Working with one piece of dough at a time, and keeping the others covered with a tea towel, roll the dough into a ball. Push through the center of the ball using both thumbs to make a hole. Then, continue to stretch the bagel out until it reaches about 4 inches across. Be sure not to flatten the bagel too much throughout this process. Place completed bagels about 2 inches apart on the previously prepared baking sheets and cover with plastic wrap. Repeat until all pieces of the dough have been shaped.
Securely cover the bagels with plastic wrap. Allow dough to proof overnight in the refrigerator for 12 - 18 hours.
Arrange the oven racks to the upper and lower thirds of the oven. Place a pizza stone on each of the racks, then heat oven to 450°F. Allow the oven and pizza stones to preheat for at least 30 minutes.
Fill a large dutch oven about halfway full with lukewarm water. Remove the bagels from the refrigerator. They will have puffed up slightly overnight. To test that the bagels have proofed long enough, gently place the bagel on the lukewarm water. If it floats, the bagels are ready to go. Pat the bagel dry and return it back to the covered baking sheets until the water begins to boil. If it sinks, the dough needs more time to proof. Remove baking sheets from the refrigerator and allow the bagels to sit at room temperature, still covered, until they float. Check every 15 minutes until they float.
Once the bagels float, begin to boil the water over high heat in the dutch oven. Once the water is at a rolling boil, add in molasses, a tablespoon at a time, until the water is dark brown.
Gently place as many bagels into the boiling water as will comfortably fit without over crowding the dutch oven. Allow the bagels to boil for 30 seconds on the first side, then flip and boil for an additional 30 seconds on the second side. Using a slotted spoon, remove the bagel from the boiling water and place on a wire rack to cool. Repeat until all of the bagels have been boiled.
Carefully, remove the hot pizza stones from the oven. Transfer the cornmeal from the original baking sheets to the hot pizza stone to prevent sticking. Place bagels on the stone about 2 inches apart. Bake for 15 -19 minutes, rotating shelves halfway through, until bagels are deeply browned and shiny on top. Keep an eye on your bagels (without opening the oven door) to make sure they're not getting too dark. Remove from the oven and let cool completely on a wire rack.