Preheat oven to 350°. Grease a 9×5-inch loaf pan with oil.
In a bowl, whisk together flour, baking powder, sugar, garlic salt, onion powder, and peppers. Fold in cheese.
In a medium bowl, whisk together milk, sour cream, melted butter, and egg. Fold milk mixture into flour mixture, stirring until just combined. Pour batter into prepared pan, smoothing top with an of set spatula.
Bake for 45 to 50 minutes. Let cool for 10 minutes. Remove from pan, and let cool for 1 hour more on a wire rack. Slice and serve with butter.
Recipe by Southern Lady Magazine at https://southernladymagazine.com/cheddar-cheese-biscuit-loaf-recipe/