Preheat the oven to 350 F/180 C. Lightly grease the bottom of three 8-inch cake pans and line the bottoms with a round of parchment paper.
In a medium bowl, whisk together the flour, baking powder, baking soda, salt, and cinnamon and set aside.
3 ½ cups all-purpose flour, 2 teaspoons baking powder, ¾ teaspoons baking soda, 1 teaspoon salt, 2 teaspoon cinnamon
In a stand mixing bowl, cream the butter, sugar, and oil together for 3 minutes until white and fluffy.
¾ cup unsalted butter room temperature, ¼ cup canola oil, 1 ½ cups granulated sugar
Mix in the eggs one at a time, mixing very well after each addition until completely combined. Scrape down the bottom and sides of the bowl.
3 Large eggs room temperature
Mix in the vanilla and sour cream.
1 tablespoon vanilla, ¼ cup sour cream or greek yogurt room temperature
Add a third of the dry ingredients and mix until almost combined, then pour in half of the buttermilk. Continue alternating the buttermilk and dry ingredients until everything is combined. Scrape down the sides and bottom of the bowl to make sure everything is well combined.
1 ¼ cup Buttermilk room temperature
Evenly distribute the batter into all three cake pans. (About 471 grams in each)
Bake the cakes directly on the middle rack for 18-20 minutes, or until a toothpick inserted into the center comes out clean.
Let them cool on a wire rack for 15 minutes, then run a spatula around the sides of the pans and turn them out onto the rack to finish cooling completely.