Melt soup butter in wide 6-quart pot over medium. Cook onion and pepper 7 minutes; stir tablespoon soup flour 1 minute.
Gradually add broth, then corn, ham, and pepper. Simmer 10 minutes until vegetables tender and ham 165°F.
Add cup soup milk; gently simmer. Mix dumpling flour, cornmeal, baking powder, and salt; rub in cold butter to small crumbs.
Stir separate 1/2 cup dumpling milk into dry mixture just until soft dough forms. With two spoons, drop twelve equal small spaced mounds over simmering soup.
Cover tightly; gently simmer 14 to 16 minutes without lifting lid. Split dumpling; center should be fluffy without wet dough. Cover and cook 2 minutes more if needed.
Rest off heat 3 minutes. Divide among six bowls with two dumplings each.