Savory Breakfast Muffins {Freezer Meal}

Name: Savory Breakfast Muffins {Freezer Meal}
Prep time: 5 min
Cook time: 25 min
Total time: 30 min
Cuisine: American
Ingredients: Cooking spray; 1-2 tablespoons olive oil or avocado oil; 1 medium-sized green or red pepper, finely chopped; ½ medium-sized onion, finely chopped; 2 cups Bisquick (all-purpose baking mix) (see Gluten-free option in Notes); 1 cup cornmeal; 1/2 teaspoon salt; 1/4 teaspoon pepper; ¼ teaspoon garlic powder; 3 eggs; 1½ cups buttermilk; 5 tablespoons melted butter; ½ lb cooked, drained, and crumbled breakfast sausage OR 1 cup chopped cooked ham (or more if you want!); 2 cups shredded cheddar cheese