Preheat your oven to 350°F (175°C) and grease a standard loaf pan.

In a large mixing bowl, whisk together flour, baking powder, salt, and granulated sugar.

Create a well in the dry mixture and add buttermilk, egg, canola oil, and vanilla extract. Stir until just combined.

In another bowl, mix brown sugar and cinnamon together for the cinnamon sugar mixture.

Layer one-third of the batter in the prepared pan, sprinkle the cinnamon sugar on top, and repeat two more times.

Swirl a knife through the batter to create marbled effects, being careful not to overmix.

Bake for 45-50 minutes until golden; test doneness with a toothpick.

Cool the bread in the pan for 10 minutes, then transfer to a wire rack.

Combine cream cheese, powdered sugar, milk, vanilla extract, and salt for the glaze, mixing until smooth.

Drizzle the glaze over the cooled bread and serve.