Step 1

Preheat oven to 375° F. Line two muffin pans with cupcake liners and set aside.

Step 2

Place the 2 cups of root beer for the buttercream in a saucepan and set over high heat. Bring to a boil and then reduce heat to medium to simmer until reduced to approximately 1/2 cup. Pour into a mason jar and place in the fridge to cool.

Step 3

Meanwhile, prepare the cupcakes: In a large mixing bowl, beat the cake mix and 1 cup root beer until light and completely combined (about 2 minutes). Fill each cupcake about 2/3 of the way full.

Step 4

Bake the cupcakes for 18-22 minutes, until a toothpick inserted in the center comes out clean.

Step 5

Allow the cupcakes to cool for 10 minutes in the tray then transfer to a cooling rack to cool completely while you prepare the buttercream.

Step 6

Place the butter and powdered sugar in a large mixing bowl and beat until well combined (about 2 minutes). Add 2 Tablespoons of your reduced root beer syrup, then taste and adjust with more root beer syrup as needed to reach desired taste and consistency.

Step 7

Transfer buttercream into a piping bag and pipe onto cooled cupcakes, starting at the edge and moving into the center. Place a maraschino cherry on top of each cupcake before serving, if desired.