Heat oven to 360 degrees.

In a medium sized bowl mix together the flour, sugar, salt and baking powder.

Cut chilled butter into chunks and using pastry cutter (or kick it old school and use two butter knives in a criss cross motion like my mom) work the butter into the flour mixture until course crumbs form and there are no chucks of butter left larger than a pea size.

Measure 1 Cup of milk (I generally use 1% or 2%)  into a 2 cup measuring glass (it will nearly double in volume).

Add the vinegar and then the baking soda and stir with a spoon. It should bubble and froth up immediately and get thicker. If it does not, add another splash of vinegar - the original recipe simply states add a splash of vinegar (this is the part my mother speaks to about the sound from vigorously stirring changes). Also it will significantly increase in volume.

Add the milk mixture into the flour mixture and combine.

With clean hands knead the mixture until it comes together, either in the bowl or on a floured surface.

Flour a surface generously and roll out the dough (also with a well floured rolling pin) to about 16" x 12". You do want it on the thicker side (even if  your own mother is not there to remind you of this repeatedly). Keep in mind this is a rustic recipe - so perfect edges need not apply.

Generously spread the softened (very soft room temperature, but preferably not melted) butter over the entire surface. This is best done with your fingers.

Next sprinkle the brown sugar evenly over the butter, then sprinkle your cinnamon on top.

Starting with wide end closest to you, begin rolling the dough up. If the dough sticks a little to the board, add extra flour to your fingers and at the base where it meets the surface. Continue rolling until fully rolled up.

Shape the roll lightly with your hands so as to get an even size and shape. Using a floured, serrated knife, cut the roll into 1" slices.

Place on baking stone ware or a parchment lined cookie sheet about a 1/2 inch apart or so.

Bake in 360 degree oven for 12 - 15 minutes until basically done.

Then turn the oven to broil, and while watching carefully, allow the biscuits to cook for another 1-2 minutes. This melts any remaining sugar and browns up the tops wonderfully. It makes a big difference in my opinion - otherwise you get brown sugar that can still be grainy (which really no-one seems to mind but me...). These biscuits are still perfectly good without this step as well, it's just my (and my mom's) preference.

Remove from oven and devour (and possibly burn tongue - so probably wait 5 minutes if you can).