Preheat the oven to 350℉. Line a 12 cup muffin pan with cupcake liners. Set aside.
In a medium bowl, sift the flour, baking powder, baking soda, salt, and cinnamon. Set aside.
1 3/4 cups All-purpose flour, 1 tsp Baking powder, 1/2 tsp Baking soda, 1/2 tsp Salt, 2 tsp Ground cinnamon
Using a mixer, beat the butter, oil, and brown sugar. Beat for 2 minutes on high speed.
1/2 cup Unsalted butter, 2 TBSP Oil, 3/4 cup Brown sugar
Add in vanilla, eggs, and sour cream. Mix on medium and mix until combined. Make sure to scrape the bowl using a baking rubber spatula.
1 tsp Pure vanilla extract, 2 Large eggs, 1/4 cup Sour cream
Add in half of the flour and half of the buttermilk. Mix on low speed until starting to combine. Then, add the rest of the flour and buttermilk. Mix on low until just combined. Take off the mixer and scrape the bowl.
1/2 cup Buttermilk
Use a large cookie scoop to scoop the batter and fill each cupcake 2/3rds full.
Bake for 15-18 minutes. Bake until a toothpick inserted comes out clean.
Let the cupcakes sit in the hot pan for 10 minutes before transferring to a cooling rack. Cool the cupcakes completely before filling and decorating.