1 stick butter at room temperature
4+ cups powdered sugar
fine salt
flavoring of your choice (typically vanilla, but in this instance, tangerine and chocolate)

Tangerine syrup:
½ cup tangerine juice
½ cup Meyer lemon juice (or ¾ tangerine and ¼ lemon if you can’t find Meyers)

½ cup 60% cacao or more dark chocolate chips melted and cool

Boil tangerine and Meyer lemon juice until it’s reduced down to ¼ cup.

Beat butter for at least two minutes. Slowly add in the powdered sugar until it reaches your desired consistency. Then add in the tangerine syrup. You may need to add more powdered sugar to get the frosting thick and glossy but still spreadable.

Once you’ve used what you need for the middle layer, beat in the melted chocolate to create your chocolate tangerine buttercream frosting for the outside of the cake.