Prepare all the required ingredients. Soften the butter at room temperature beforehand.
Combine soft butter, sugar and egg in a deep bowl.
Grind all ingredients with a fork until smooth.
Add flour, cocoa, salt and baking powder.
Stir and add the oatmeal.
Stir everything again and put the dough in the refrigerator for 30 minutes.
With wet hands, form small balls about the size of a walnut, place on a baking sheet and lightly flatten on top with your hands. Bake at 180 degrees for about 15 minutes.
Very tender, tasty and aromatic chocolate oatmeal cookies are ready.