Line 2 baking sheets with parchment paper or Silpat. 

In a food processor pulse the oats for a minute or so to grind them into a meal, it doesn’t have to be fine ground it’s just to break them up a bit, there should still be some oats still visible. 

In a medium bowl add the oats and mix in the whole-wheat flour, baking powder, and salt. 

With your fingers or a pastry blender, rub in the brown sugar until there are no big limps. 

Using just your hands, or a pastry blender, blend in the cold butter until there are no big clumps visible, this is not like American biscuit dough you can work this dough to make sure the butter is blended well, the mixture should look like bread crumbs with no visible butter chunks. 

Sprinkle the milk over the flour mixture and mix it in with a fork or spoon. The dough will be just slightly sticky. 

Knead it for a bit on a clean work surface sprinkled with a little flour. 

Form onto a flat disk about 2 inches in thickness, wrap the dough in plastic wrap and let rest in the fridge for at least 30 minutes. The reason here is to let the moisture be absorbed into the dough it doesn’t have to be cold.

When the dough feels firm, roll out onto a floured work surface to about 1/8 inch thick. 

Using a round 3” cookie cutter cut out as many as possible,

Place each cut biscuit onto the prepared baking sheets.

The leftover dough can be re-rolled and cut. But, be careful not to over work the dough. You should get 24 biscuits.

Allow the dough to rest in the fridge for 20 minutes while you pre-heat the oven to 350°. Letting the dough chill will help the biscuits keep their shape while baking.

Bake for 20 -25 minutes, rotating the cookie sheets at 10 minutes. 

Check at 20 minutes, they should be just golden around the edges. Do not over bake. 

Let cool on a rack. They will keep a week or more sealed in a plastic container or bag.