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

In a medium bowl, whisk together the all-purpose flour, sugar, baking soda, baking powder, salt, and cinnamon.

In a large bowl, combine the milk and lemon juice. Let sit for 5 minutes, then add vegetable oil, vanilla extract, and eggs, whisking until combined.

Gradually add dry ingredients to wet mixture, stirring gently until just combined.

In a small bowl, mix brown sugar, cinnamon, and melted butter for the swirl.

Pour half of the batter into the loaf pan, add three lines of the cinnamon mixture, and gently swirl.

Add the remaining batter and swirl the remaining cinnamon mixture on top.

Bake for approximately 50 minutes or until a toothpick comes out clean.

Let the bread cool in the pan for 5-10 minutes before transferring to a cooling rack.