Add the soft unsalted butter and caster sugar to a clean blender.

Pulse into a smooth mixture for 30 seconds. Then add 3,5 oz (100 g) of the dark chocolate chunks.

Pulse again. Add the plain flour, baking powder, baking soda and cinnamon together with a pinch of salt.

Blend again. Then add the cocoa and the egg.

Pulse into a very firm and thick chocolate cookie dough.

Transfer it onto a clean surface and knead it for a minute.

Then roll it out until about ⅓ inch (8 mm) thickness. If the dough sticks too much, put it in the fridge for a couple of minutes to chill. Cut out cookies using whatever shape you want. Mine were about bite-size.

Transfer the cookies onto a piece of baking paper.

Bake the chocolate cookies in a preheated oven at 359°F (180°C) for 15 minutes. After that let the baked cookies cool fully at room temperature. Then add the rest of the dark chocolate chunks to a small saucepan.

Place it over medium-low heat and gently melt the chocolate.

Drizzle the melted chocolate with a spoon over the cookies.

Put them in the fridge to dry. Serve.