In a mixing bowl fitted with the dough hook, combine the yeast, water and approximately 1 teaspoon of the sugar. Gently stir to hydrate the yeast. Allow to sit until foamy, 3-5 minutes. Add the yolks, bread flour, rest of the sugar, and 20 grams malt powder or malt barley syrup. (If using instant yeast, combine all ingredients except the salt and continue from here.) Knead on a medium-low speed for about 7 minutes. Then, with the mixer on a low speed, slowly add the salt. Once combined, increase the mixer to medium-low, and continue kneading an additional 3-5 minutes. The salt should be fully absorbed (you should not feel the salt when you touch the dough) and the dough should be very smooth.
To make sure the gluten is fully developed, do a windowpane test. Take a small piece (approximately 1 teaspoon) of dough and stretch it between your fingers. It should form a “window pane”, meaning it should get thin enough that it is translucent without it ripping. If it is not at that point yet, continue kneading in the machine at 1 minute intervals or knead by hand until it passes the test. If it feels too dry (which could also cause it to rip), add 1 teaspoon of water. The dough should barely be tacky.
Divide the dough into six equal portions, each approximately 125 grams (If you want your bagels to each be equal, weigh the entire dough and divide the weight by 6.) Shape each one into a ball, covering with plastic wrap as you shape each ball. Taking one dough ball at a time, flatten the ball with your fingers into an oval/rectangle, approximately four inches by six inches, so that the long part of the oval/rectangle is horizontal in front of you. Fold over the top third onto itself, pressing down. Make another fold over the remaining portion of the dough. Pinch the ends of the log together. With both your hands, roll the dough into a rope, approximately 8-9 inches long. In between rolling, it is a good idea to squeeze the log to release any air bubbles within it. Cover with plastic wrap. Repeat with remaining dough balls. Allow the six ropes to rest for 15 minutes.
Attach the ends of each rope to form bagels. Place each bagel on a baking sheet lined with parchment paper. Place the tray, tightly covered in plastic wrap, in the refrigerator overnight.
In the morning, remove the tray from the refrigerator and allow the bagels to come to room temperature, approximately 45-60 minutes.
Approximately 30 minutes before you plan to boil the bagels, preheat the oven to 425°F. Line a baking sheet with parchment paper and set aside.
Using a pot large enough to comfortably hold 2 or 3 bagels at a time, bring a pot of water to a boil and add 2 Tablespoons of non-diastatic malt powder or 1 Tablespoon malt barley syrup. (I use a 4½ quart pot and fill it up approximately half way with water.) Place 2 or 3 bagels at a time into the boiling water for 30 seconds. Flip each bagel and boil for an additional 30 seconds. Using a strainer or a slotted spoon, remove each bagel from the water, coat with any desired toppings, and place on the prepared baking tray. Repeat with the rest of the bagels.
Bake the bagels for 16-20 minutes, until the tops are nicely browned.