Preheat the oven to 350 degrees. Prepare your muffin tins by placing cupcake liners, set aside.
In the bowl of a stand mixer, combine ½ cup butter and 1 cup sugar on low for 2 - 3 minutes until creamed and smooth.
Add in 2 eggs, ¾ cup Rumchata and 2 teaspoon vanilla. Mix on medium low until combined.
Add in 1 ½ teaspoon cinnamon, ½ teaspoon salt, 1 ½ teaspoon baking powder and 1 ½ cup flour. Mix on low - stopping the machine to scrape the sides often and mixing again.
Scoop batter into cupcake liners filling each about ⅔ of the way full.
In a small bowl, combine ½ cup sugar and 2 tablespoon cinnamon for the topping. Sprinkle about a half teaspoon of the cinnamon sugar mix over the cupcake batter.
Bake for 14 - 16 minutes or until center is set.
For the frosting - in the bowl of a stand mixer, combine 1 cup butter, 1 teaspoon vanilla, 1 teaspoon salt, 4 tablespoon Rumchata and 2 cups of the powdered sugar. Mix on low until combined.
Add in the remaining powdered sugar and continue to mix on low until combined.
Bump up the speed to medium and whip for an additional minute, until the frosting is smooth and fluffy looking.
Transfer the frosting to a piping bag fitted with a large star tip.
Add a large mound of frosting to the top of each cupcake and sprinkle with remaining cinnamon sugar mixture.