Preheat oven to 350F and grease either 3 6inch pans or 2 8inch pans
Cream butter and sugars on medium high until smooth and fluffy
Add eggs one at a time with mixer on low until fully incorporated
Add vanilla extract
Combine flour, baking powder, salt, and cinnamon in a separate bowl; mix thoroughly
Add 1/3 of flour mix to the mixer on low. Add 1/2 the buttermilk. Scrape the sides, continue to mix, and add another 1/3 of flour mixture. Add the rest of the buttermilk, then add the rest of the flour mixture
Pour into pans and bake for 30-35 minutes