Place a piece of parchment on your surface and dust it with flour. Empty biscuit dough onto the paper, then dust it with flour.
Flatten the dough and fold it into thirds like folding a letter. Flip it over and dust with more flour. Repeat this step 3 more times, adding flour to the paper and dough as needed to prevent sticking. (You can and should use all of the four that was set aside)
Using your biscuit cutter as a guide, flatten the dough so it will fit 2 rows of 3 biscuits (for a total of 6).
To cut each biscuit, place the cutter on the dough and press straight down, then pull straight out. Do not twist because that will seal off the layers. Between each cut, it is helpful to wipe any dough off the cutter to prevent sticking.
Gather the scraps and shape to fit 2 more biscuits. Gather the final scraps and if there is enough, make one more biscuit (this last one might be thinner).
Spray a cast iron skillet with oil, then place into it, making sure they are all touching each other (this helps them rise vertically rather than in all directions).
Bake at 425F/220C for 5 minutes, then reduce temperature to 325F/165C and bake for another 10 minutes. Remove from the oven and the pan immediately, placing them on a wire cooling rack.