Warm 210 ml of whole milk until lukewarm. Combine it with granulated sugar, active dry baker's yeast, and 2 tablespoons of T45 wheat flour.

Cover the mixture with the clean kitchen towel. Rest it for 10 minutes until the yeast is activated.

Sift the remaining T45 wheat flour into the yeast mixture. Add salt and milk powder.

Mix the dough with the silicone spatula. Knead in the softened unsalted butter until the dough is smooth.

Knead the dough for about 10 minutes. Cover it and let it rise for 60 minutes.

Divide the risen dough into two equal portions. Place one portion in a separate mixing bowl.

Add unsweetened cocoa powder and neutral vegetable oil to one dough portion. Knead until the cocoa is fully incorporated.

Cover both dough portions. Let them rise for another 60 minutes.

Roll the plain dough into a rectangle. Roll the chocolate dough into a matching rectangle.

Place the chocolate dough rectangle over the plain dough. Roll the stacked dough halfway into a log.

Cut the unrolled end into narrow strips. Twist the strips to create the braided pattern.

Coil the shaped dough onto itself. Transfer the brioche into the prepared loaf pan.

Cover the loaf pan with the clean kitchen towel. Let the brioche rise for 60 minutes.

Preheat the oven to 180°C. Whisk the egg with 15 ml of whole milk for egg wash.

Brush the egg wash over the risen brioche. Bake for 15 to 20 minutes until golden brown.

Remove the brioche from the loaf pan. Cool it before slicing and serving.