Place 100g dark chocolate and 30g butter in a bowl.

Warm water in a pot, turn off the heat, and place the bowl with chocolate and butter over the pot. Stir until melted.

In another bowl, whisk 1 egg and 30g sugar until combined.

Add the melted chocolate and butter mixture to the egg and sugar mixture. Stir until smooth.

Sift 1 tbsp cocoa powder, 1 tsp baking powder, 50g cake flour, and a pinch of salt into the bowl. Mix until no dry flour is visible.

Fold in 50g chocolate chips until evenly distributed.

Chill the dough in the refrigerator for 30 minutes.

Scoop the dough using an ice cream scoop and place on a parchment-lined baking tray.

Bake in a preheated oven at 180°C (356°F) for 10 minutes.

Let the cookies cool on the parchment paper before transferring to a cooling rack.