Spray the bottom of a 9x9 glass baking dish with nonstick spray.
In a large mixing bowl whisk together the flour, baking powder, sugar and salt to remove any lumps.
Place the tablespoons of cold butter into the bowl of flour. Toss to coat the pieces of butter with flour. Using a fork break up the butter pieces until crumbly and about the size of peas. Stir to toss the crumbled butter with flour.
Place the bowl of flour/butter into the freezer for a few minutes to get the butter cold again. (The secret to flaky biscuits)
Remove the bowl from the freezer. Pour in the 7-Up and mix together to form dough into a ball.
On a lightly floured surface roll or pat out the dough into a 9x9 square. Using a sharp knife cut into nine squares (tic-tac-toe pattern).
Place cut biscuits into the prepared pan with sides touching. Bake at 450 degrees for 15 minutes or until golden brown.
Notes
Cut the butter into tablespoons and then place back in the fridge until you are ready to add the butter to the flour. The colder the butter the better.
Recipe can be easily doubled (you probably will want to do that they are so good)