Preheat your oven to 350°F (175°C) and grease a 9 x 5-inch loaf pan generously with butter or oil, then dust lightly with flour.

In a medium bowl, whisk together the dry ingredients: flour, sugar, baking soda, baking powder, salt, and cinnamon.

In a larger bowl, combine milk and lemon juice. Let sit for 5 minutes. Then whisk in the vegetable oil, vanilla extract, and eggs until smooth.

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

In a small bowl, mix together brown sugar, cinnamon, and melted butter until well combined.

Pour half of the batter into the prepared loaf pan. Drizzle cinnamon swirl mixture and create a swirl with a skewer or knife. Repeat with the remaining batter and swirl.

Bake for 50-55 minutes or until a toothpick inserted comes out clean. The aroma of cinnamon will fill your kitchen.

Remove from oven and let cool in the pan for 5-10 minutes, then invert onto a wire rack to cool completely before slicing.