Preheat oven to 350°F (175°C) and grease a 9×5-inch loaf pan.

In a small bowl, mix cinnamon and brown sugar for the swirl; set aside.

In a medium bowl, whisk flour, baking powder, salt, and brown sugar.

In another bowl, mix egg, milk, melted butter, and sourdough discard until smooth.

Combine wet and dry ingredients gently until just mixed.

Pour half the batter into the pan.

Sprinkle ¾ of the cinnamon sugar mixture on top.

Add remaining batter and top with the rest of the swirl mixture.

Use a knife to create a swirl pattern.

Bake for 45–50 minutes until a toothpick comes out clean.

Cool before slicing.

This Sourdough Discard Cinnamon Bread should have a soft crumb and a rich cinnamon swirl throughout.