For the Cinnamon Cupcakes
1-Preheat oven to 350°F (176°C) and prepare: Preheat oven to 350°F (176°C) and prepare a cupcake pan with cupcake liners.
2-Combine the sugar and cinnamon for the: Combine the sugar and cinnamon for the cinnamon sugar swirl in a small bowl and set aside.
3-Combine the flour, cinnamon, baking powder and: Combine the flour, cinnamon, baking powder and salt in a medium sized bowl and set aside.
4-Add the butter, oil, sugar and vanilla: Add the butter, oil, sugar and vanilla extract to a large mixer bowl and beat together until light in color and fluffy, about 3-4 minutes. Do not skimp on the creaming time.
5-Add the eggs one at a time,: Add the eggs one at a time, mixing until mostly combined after each. Scrape down the sides of the bowl as needed to be sure all ingredients are well incorporated.
6-Add half of the dry ingredients to: Add half of the dry ingredients to the batter and mix until mostly combined.
7-Slowly add the milk and mix until: Slowly add the milk and mix until well combined. The batter may look a little curdled, but that’s ok.
8-Add the remaining dry ingredients and mix: Add the remaining dry ingredients and mix until well combined and smooth. Scrape down the sides of the bowl as needed to be sure all ingredients are well incorporated. Do not overmix the batter.
9-Fill the cupcake liners with the batter: Fill the cupcake liners with the batter and add the swirl. Add one tablespoon of cake batter to the bottom of each cupcake liner. Add ¼ teaspoon of the cinnamon sugar swirl to each cupcake liner on top of the cake batter in an even layer. Add two more layers of cake batter and cinnamon swirl, for a total of three layers of cake batter and three layers of cinnamon swirl. Top each cupcake with about half a tablespoon of cake batter.
10-Bake for 15-18 minutes, or until a: Bake for 15-18 minutes, or until a toothpick inserted into the center comes out clean. Remove cupcakes from the oven and place on a cooling rack to cool.

For the Cinnamon Sugar Frosting
11-Add the butter to a large mixer: Add the butter to a large mixer bowl and beat until smooth.
12-Add about half of the powdered sugar: Add about half of the powdered sugar and mix until smooth and well combined.
13-Add the cinnamon, vanilla extract and 1-2: Add the cinnamon, vanilla extract and 1-2 tablespoons of the water or milk and the salt to the frosting and mix until well combined.
14-Add the remaining powdered sugar and mix: Add the remaining powdered sugar and mix until smooth. Add additional milk or water as needed to get the right consistency.
15-Pipe the frosting onto the cupcake and: Pipe the frosting onto the cupcake and sprinkle with any remaining cinnamon sugar swirl. Keep in mind that the cinnamon sugar on top will soak up moisture as the cupcakes sit, so if you want the obvious look of the cinnamon sugar you see in the photos, you’ll want to add that just before serving.