Preheat your oven to 350°F and line a cupcake pan with paper liners.
Cream together the softened butter and sugar until smooth
Add the eggs, vanilla, and milk. Mix until fully blended.
Add flour, baking powder, salt, and cinnamon. Mix well, scrape down the bowl, and stir again until fully incorporated.
Divide the batter evenly into the liners, filling each about ⅔ full. In a separate bowl, mix cinnamon and sugar, and sprinkle about ½ teaspoon on top of each cupcake.
Bake for 15 minutes or until a toothpick comes out clean.
For the frosting, beat butter, vanilla, salt, cinnamon, and powdered sugar on low until combined.
Then increase the speed to medium and beat for 2–3 minutes until fluffy.
Add the frosting to a piping bag with a large star tip. Pipe tall swirls on each cooled cupcake and sprinkle with the remaining cinnamon-sugar mixture.