In each of 2 medium saucepans, heat 2 tablespoons butter over medium-low heat. Add half of the onion and garlic to each pan and cook, stirring frequently, until softened, about 7 minutes. Add the corn to one pan, and add the roasted red peppers with their brine along with the croutons and cumin to the other pan. Add 1 can chicken broth to each pan and bring to a boil. Reduce the heat and simmer both soups, stirring occasionally, for 20 minutes. Stir the sour cream into the corn soup.
Using a hand blender, puree each soup in its pan; season to taste with salt and pepper. Season the pepper soup with hot sauce to taste. To serve, using two measuring cups, pour the soups simultaneously into opposite sides of each bowl; top with croutons.