Preheat oven to 350.
Insert paper liners into cupcake pans.
Whisk 1 cup sour cream, 1/2 cup vegetable oil and 1 tsp vanilla extract together.
Add one egg at a time, sitrring constantly.
Alternate adding cake mix, 1/4 cup water and 1/2 cup buttermilk.
Fill liners 2/3 full.
Bake for 14 to 18 minutes - an inserted knife should come out clean
Melt 1/3 cup chocolate chips and 2 tbsp heavy cream together in the microwave.
Mix in 1 tsp peppermint extract and 1/4 cup powdered sugar.
Use a squeeze bottle to fill the cupcakes with mint filling.
Pipe frosting onto the cupcakes.
Top cupcakes with extra mint filling and an Andes mint.
