Creating your own Cinnamon Swirl Donut Loaf can be a rewarding process if you follow these simple steps:

1. Preheat the Oven: Start by preheating your oven to 350°F (175°C). Grease and flour a 9×5-inch loaf pan.
2. Mix Dry Ingredients: In a bowl, whisk together the flour, baking powder, baking soda, ground cinnamon, and salt. Set aside.
3. Cream Butter and Sugar: In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.
4. Add Eggs: Beat in the eggs, one at a time, ensuring each is thoroughly combined before adding the next.
5. Incorporate Wet Ingredients: Add the buttermilk and vanilla extract, mixing until smooth and well-integrated.
6. Combine Mixtures: Gradually add the dry mixture to the wet ingredients, stirring just until combined. Be careful not to overmix.
7. Prepare Cinnamon Swirl: In a small bowl, mix the brown sugar, ground cinnamon, and granulated sugar until uniform.
8. Layer Batter: Pour half of the batter into the prepared loaf pan. Sprinkle half of the cinnamon swirl mixture on top.
9. Add Remaining Batter: Pour the remaining batter over the swirl and then sprinkle the rest of the cinnamon mixture on top. Use a knife to swirl it through the batter gently.
10. Bake: Place in the preheated oven and bake for 40-45 minutes or until a toothpick inserted into the center comes out clean.
11. Cool: Once baked, remove the loaf from the oven. Allow it to cool in the pan for about 10-15 minutes, then transfer to a wire rack to cool completely.

Following these steps will ensure a moist, flavorful loaf that delights your senses and those of your guests.