Preheat the oven to 340F/170C. In a bowl, combine cake flour, sugar, and milk cocoa. Use a whisk to mix well. It's ok once there are no lumps.
Mix in vegetable oil and milk.
Use a rubber spatula to mix with a cutting motion. It's good if you can mix it into a single lump. If you can't, wrap it up and knead it from the outside until it becomes a single lump.
Make bite-sized balls (about 10 g) and lay on a baking pan covered with baking paper. Bake at 340F/170C for 15-20 minutes.
After they've baked, let cool on the baking pan. The dough will still be soft so let them cool without touching them. Once they've cooled, sprinkle powered sugar on top.
Story Behind this Recipe
These are milk cocoa cookies.
Adjust the oven temperature and baking time accordingly. They'll be soft after cooking. Once you let them cool, they harden. Please be careful not to over bake. In Step 3, if you couldn't form it into a single lump, wrap it up and knead from the outside until it becomes a single lump.