To make oat flour, place the 2/3 cup of oatmeal in a food processor with a metal chopping blade. Grind the oatmeal until it resembles coarse flour.

In a large bowl, combine the all-purpose flour, ground oats, baking powder, salt, and sugar and mix with a spoon* until well blended. Using a pastry blender (or your fingers), cut in cold butter until mixture resembles coarse sand. Stir in cold buttermilk and form dough into a ball. Cover with plastic wrap and place in the refrigerator for 30 minutes.

Preheat oven to 350 degrees (F). On a floured surface, roll out dough until it's just under 1/4 inch thick. Using a fork, prick the dough all over. This will prevent the cookies from buckling as they bake. Using a 2-1/2 inch biscuit cutter (or the rim of a glass), cut out cookies and place them on a parchment-lined baking sheet, spacing them 1 inch apart.

Bake for 15 minutes or until golden brown on top. remove to a cooling rack.

In a microwave-safe bowl, melt the chocolate, heating it for 30 seconds at a time. Stir well between each heating until chocolate is velvety smooth. You can either dip the bottom of the cookies into the chocolate or dollop a spoonful on the bottom of each cookie. Using a knife, smooth the chocolate, making sure it covers the entire bottom of the cookie. Place cookies chocolate side up on cooling rack. Allow the chocolate to cool completely before serving

I prefer to make this cookie dough by hand, as my mum taught me. However, if you have a food processor and are making the oat flour, by all means, make the dough in the food processor. Using a metal chopping blade, blend all dry ingredients together before adding the cold butter. Add the butter and blend again until the dough resembles coarse sand, then add the buttermilk for the final blend. Easy-peasy!