In a mixing bowl, combine the softened butter with the sugar;
Add the eggs, one at a time and mix very well;
Add the flour (or a mix of flours);
When it is well combined, add the oat-bran and the cocoa powder;
Now add the chocolate chips, and sieve in the baking powder not to make any lumps;
Combine well, but not work the mixture too much;
Make walnut-side scoops of the mixture (if they are they same size they will bake evenly) with your wet wet hands, flatten them to give them a round shape;
Place them evenly spaced onto a baking tray lined with parchment paper;
Preheat the static oven and bake at 180°C (356°F);
Let them cool;
Extra: in the meanwhile you may melt some chocolate in the microwave or “en bain Marie”: you can sandwich two cookies together with a dollop of chocolate;
If you want more rustic and tempting cookies, lay more chocolate chips onto the baking tray, then place the scoops of mixture and top with more chips. Gently tap the cookies so the chips will evenly stick to them. Your cookies will get unbelievably mouthwatering.
More tempting version: replace oat bran with dark cocoa powder for double chocolate cookies. Very dark chocolate ones, those I love for my breakfast!