Preheat oven to 450 degrees. In a large bowl, cut sour cream into biscuit mix. Add 7-Up, stir to combine. The dough will be soft and sticky.

Sprinkle additional baking mix on your work surface and shape the dough into a 9-inch square. Cut dough into 9 squares. I like to use a pizza cutter to do this.

Melt butter in a 9-inch square baking dish. Place cut biscuits in pan. Bake for 12-14 minutes until golden. Brush tops of biscuits with additional melted butter.