Cornbread Muffins with Cajun Butter

Name: Cornbread Muffins with Cajun Butter
Ingredients: Nonstick cooking spray, for greasing the muffin tin; 1 1/2 cups buttermilk; 1/4 cup vegetable oil; 1 large egg; 2 cups self-rising cornmeal mix, such as Martha White; Pinch of salt; 1 stick unsalted butter, softened; 1/2 teaspoon brown sugar; 1/2 teaspoon chili powder; 1/2 teaspoon dried oregano; 1/2 teaspoon cayenne pepper; 1/2 teaspoon garlic powder; 1/2 teaspoon salt; 1/2 teaspoon ground black pepper