Bring a large pot of heavily salted water to a boil. Once boiling, add the pound of pasta and cook about 7-8 minutes. Add the 4 cups broccoli florets and cook about 1-2 minutes more or until broccoli is cooked but still retains bite. Drain well and rinse with cold water to stop cooking. Shake in the colander to get the excess water off.
Place pasta and broccoli in a large bowl, add the 8 ounces diced ham, the 1 cup diced cheddar, the diced bell pepper, the sliced red onion, and the 4 cups baby spinach and stir to combine.
In a medium bowl combine the 1 1/4 cups yogurt, the 1 cup sour cream, the 3 tablespoons vinegar, the 2 tablespoons mustard, the 4 teaspoons salt, 1 tablespoon rosemary, and 1/2 teaspoon black pepper. Whisk until smooth.
Pour dressing over pasta salad and stir until well coated. Taste and add more salt and pepper if necessary. Cover and refrigerate at least 30 minutes before serving.