I started out with 2 20 oz bottles of root beer and 1 20 oz bottle of cream soda, you will need almost an entire bottle for the reductions (you can also use root beer extract if you have it available, or the soda syrups used in home made soda or Italian sodas). Reduce each soda down from 2 cups to a 1/2 cup by simmering for approximately 30 minutes.
Set your reductions aside to come to room temperature, then refrigerate the reduced cream soda syrup for use in the buttercream frosting.
Preheat your oven to 350 degrees F (175 degrees C) and grease or line your muffin pan with cupcake liners. (this recipe usually makes 12-14 cupcakes)
In a medium mixing bowl, combine the flour, baking powder, baking soda, and salt and use a fork to combine the dry ingredients. In a large mixing bowl, beat together the brown sugar, eggs and oil. Add the reduced root beer soda syrup, almond and vanilla extracts and mix until combined.
Add the flour mixture (I like to add it in gradually while mixing the batter) until the dry ingredients are just incorporated into the wet batter and the batter is thick. Add the root beer soda and mix just enough to get an even batter consistency.
Divide the batter between your cupcake liners, filling each about 2/3 to 3/4 full then bake for 16-18 minutes or until an inserted toothpick comes out clean. Cool for about 5 minutes before removing from the muffin pan to cool completely on a wire cooling rack.