Preheat oven to 450 degrees F. Pour 2 cups of Bisquick mix into a large bowl. Add in sour cream. Mix together. Pour in 7-Up soda and stir until combined. The dough will be very soft.
Sprinkle remaining 1/4 cup of Bisquick mix onto a clean counter-top and gently pat dough out to a 1-inch thick square. Use a circle biscuit cutter and cut out biscuits. (You should get 9 total).
Pour melted butter into a 9x9-inch dish. Place the biscuits into the pan, over the top of the butter. Bake, uncovered, for 9 to 10 minutes or until tops are golden brown. Serve warm and enjoy!