In a mixing bowl place bread flour, sugar, instant yeast and salt. Mix with a wire whisk to incorporate all ingredients.
Add egg and vegetable oil then mix with a spatula until rough dough forms. Fix mixing bowl in the mixer with dough hook attachment and beat at low-medium setting for 12 minutes or until dough is smooth, elastic and doesn't break when pulled.
Grease clean counter top or flat surface with a bit of oil and place dough on top to avoid dough sticking. Knead for a couple of seconds then shape it into a ball.
Transfer in another bowl and coat with thin layer of oil so it will not dry out while rising. Let it rise for 1 hour or until double in size. While waiting, prepare muffin baking tray by greasing with butter.
When dough doubled in size you know you achieved a good rise. Lightly press on the dough to release the air/gas inside. Dump the dough on the counter top and roll into a log shape. Cut and using a kitchen scale, weigh 40 grams of dough.
Place breadcrumbs in a small plate and dredge cut dough onto the bread crumbs. Arrange in a muffin baking tray and cover with a kitchen towel to rest for 20 minutes or when it doubles in size.
Sift cocoa powder and powdered sugar in a small bowl. Set aside.
While waiting for the final rise, pre-heat the oven at (375°F or 180°C°). When the dough have rested for 20 minutes, dust the top with cocoa and sugar topping. Place them in the oven and bake for 20 minutes at (375°F or 180°C°) . NOTE: baking time may vary according to oven used