Add dark chocolate and sunflower oil in a bowl over a pot with hot water. Mix and stir until melted.

Put chocolate syrup in a bowl. Let the chocolate syrup chill in the refrigerator.

Mix flour and cocoa powder. Set aside.

Beat butter and sugar till light and fluffy.

Add flour mixture. Combine gently into a dough. Add a tablespoon of milk if the dough looks slightly dry. Set the dough aside.

Take out frozen chocolate syrup and split into portions of any amount.

Spoon out a portion. Put the rest of the portions back into the refrigerator. Take the spooned portion and knead into a ball (it will melt a little).

Pinch balls of the set aside dough with a clean hand. Flatten. Clean other hand then place one of the rounded chocolate syrup balls in the dough. Seal edges and gently flatten by rounding the ball with your hands.

Place these rounded balls on a lined baking tray. Bake for 16 to 18 mins at 350°F in a pre-heated oven.

Final results in image below. Repeat process from step 9 to make more.