Preheat the oven to 350°F (175°C). Grease and flour a 9×5-inch loaf pan.
In a large mixing bowl, whisk together flour, granulated sugar, baking powder, baking soda, and salt.
In a separate bowl, whisk together buttermilk, vegetable oil, eggs, and ground cinnamon.
Gradually add the wet ingredients to the dry ingredients, stirring until just combined. Do not overmix.
In a small bowl, mix together the granulated sugar and ground cinnamon for the cinnamon sugar topping.
Pour half of the batter into the prepared loaf pan. Sprinkle half of the cinnamon sugar topping over the batter. Add the remaining batter and sprinkle the remaining cinnamon sugar topping on top.
Use a knife to swirl the batter and cinnamon sugar topping together.
Bake for 50-60 minutes or until a toothpick inserted into the center comes out clean.
Allow the bread to cool in the pan for 10 minutes, then transfer it to a wire rack to cool completely.
Dust with powdered sugar before serving, if desired.
Enjoy the comforting aroma and flavors of Easy Cinnamon Bread! Perfect for breakfast or a delicious snack!