Preheat your oven to 425°F.
Combine the Bisquick mix and sour cream into a mixing bowl with a fork. Bisquick is made from all-purpose flour, vegetable shortening, baking powder, and salt, so you can make the mixture at home if you don't have it readily available.
Gradually add the Club Soda, 7-Up, or Sprite and keep mixing until a sticky dough forms. Similar to the above recipe, make sure you don't knead the dough too much as it may toughen the biscuits. It typically doesn't take any more than ten kneads until the ingredients are fully combined.
Roll the dough into a lightly floured surface until it's about half an inch thick. Cut the biscuits into small circles using the lip of a glass (lightly coated in flour) or a 3-inch biscuit cutter. Don't twist the cutter as it may seal the biscuit’s edges, which might prevent the dough from fluffing up.
Add ¼ of the melted butter into the pan. Then, place the dough circles directly above the butter. Brush the biscuits generously with the remaining melted butter.
Bake for 20 to 25 minutes or until the biscuits turn lightly golden in color.