Preheat the oven to 400 degrees F. Toss the bread on a baking sheet with 1 tablespoon oil and season with salt and pepper. Bake, tossing halfway through, until crisp, 15 to 20 minutes.
Meanwhile, heat the remaining 1 tablespoon oil in a large pot or Dutch oven over medium-high heat. Add the sausage and cook, breaking it up with a wooden spoon, until browned in spots and no longer pink, 4 to 6 minutes. Add the onion, carrots, garlic, 1/2 teaspoon salt and a few grinds of pepper; cook until almost tender, 6 to 8 minutes.
Add the kale and cook until just wilted, about 2 minutes. Stir in the tomatoes, chickpeas, pasta, broth and 4 cups water. Cover and bring to a boil, then reduce the heat and simmer until the kale is tender and the pasta is al dente, 3 to 5 minutes. Season with salt and pepper.
Ladle the soup into bowls. Top with the croutons and season with pepper.