Before starting, determine the type of yeast you have. If using active dry yeast: combine the water and molasses and sprinkle the yeast on top of the liquid. Let it bloom for 5 minutes until slightly foamy. If using instant (bread machine) yeast, you can skip this step and add it directly to the dry ingredients.
In the bowl of a stand mixer fitted with a dough hook, combine the all purpose flour, cornmeal, dry milk powder, salt, and instant yeast (if using). Whisk to combine.
To the dry ingredients, add the water and molasses mixture (with the bloomed active dry yeast, if using) and the melted butter. Mix on low speed for 1 minute, just until combined.
Increase the speed to medium-low (speed 4 on a KitchenAid) and mix for 10 minutes. The dough should look smooth and begin to pull away from the sides and bottom of the bowl. To check if the dough is ready, do the windowpane test: stretch a small piece of dough between your fingers. If it stretches thin enough for light to pass through without tearing, it’s ready. If it tears, mix for another two minutes and test again.
Once the dough has been kneaded, transfer to a lightly floured surface and knead a few times by hand to shape the dough into a smooth ball. Place the dough back in the bowl. and cover with plastic wrap. Let it rest for 30 minutes. It won't rise much, you're just relaxing the dough.
Spray a 9x5-inch loaf pan with cooking spray and set aside. Once the dough has rested, move it onto a lightly floured surface and shape it into a rectangle roughly as wide (9") as the loaf pan. Roll the dough up tightly into a log, pinching the ends closed, and place the log seam-side down in the greased loaf pan.
Loosely cover the bread with plastic wrap sprayed with cooking spray and let rise in a warm spot for about 1 1/2 hours, or until doubled in size. The dough is ready when you gently press it with your finger and the dent stays or slowly springs back.
Once risen, you can add a pretty design by scoring the top with a sharp knife and sprinkling on extra cornmeal. Bake the anadama bread at 350°F for 30–35 minutes, until the bread has risen, browned, and the center of the bread reaches 190°F on an instant-read thermometer.
Remove the bread from the pan right away and place it on a cooling rack to keep the bottom from getting soggy. Allow the bread to cool completely before slicing.