Place butter in a 9-inch square baking pan and place in the oven to melt the butter. Watch it carefully as the butter will burn quickly and easily. Alternately, you can melt the butter in a microwave safe bowl and pour it into the baking pan.
In a medium bowl, stir the Bisquick and sour cream together. Slowly pour in 7-up. Add salt.
Spread a thin coating of flour on a large piece of parchment paper or your counter. Coat your hands with flour and sprinkle some on top of the dough.
Shape into approximately a 9-inch square. Do not knead. At this point you can cut into individual square biscuits and place in the prepared pan on top of melted butter. But I just place the dough in the pan as 1 piece and cut into biscuits once cooked. Dough will be very wet and hard to work with. You will think the whole thing is going to turn into a hot mess, but it won't.