• Please note that I have included two methods below for tangzhong making and dough kneading using either the Thermomix or conventional bread machine so do take note of the sub-headings. If you're new to breadmaking, I also suggest you read through the notes and FAQ below the recipe.
• Place the zest of two oranges and 28g castor sugar in a bowl. Rub together using back of spoon to release the essential oil and citrusy aroma, then set aside.
  
• Juice 2-3 medium sized oranges to yield a total of 150g of fresh orange juice.
• Prepare Chocolate Paste by mixing cocoa powder and milk in a separate small bowl. Set aside.

(A) THERMOMIX – Tangzhong & Dough Kneading

• To make the tangzhong, place 20g high protein flour and 100g orange juice in mixing bowl, cook for 3min/80°C/spd 3 and let stand for 15 minutes until temperature lowers down to 40°C.
• Add remaining 50g orange juice and milk, egg yolk, orange zest + sugar mixture, salt, milk powder, 270g high protein flour and yeast then knead 4min.
• Add butter, knead 1min.
• Remove dough and transfer to pastry mat. Portion out 180g of dough and place back into mixing bowl. Shape the remaining orange dough into a round ball and let proof in a warm place covered loosely with cling wrap or damp towel until doubled in size.
• Add chocolate paste into mixing bowl and knead 30 seconds until well incorporated. Transfer chocolate dough to pastry mat, and shape into round ball and let proof for an hour. Let proof covered loosely with cling wrap/damp towel until doubled in size (approx. 45-60 minutes). 
  

(B) CONVENTIONAL – Tangzhong

• Prepare tangzhong by mixing flour in orange juice and whisk together in a pot, ensuring the mixture is well combined with no lumps. Cook over medium-low heat, stirring consistently to prevent burning and sticking while you cook.
• The mixture will gradually become thicker. Once you notice that some “lines” appear in the mixture for when you stir with the spoon, it’s done. Your tangzhong is ready.
  
• Transfer into a clean bowl. Cover with a cling wrap sticking onto the surface of tangzhong to prevent it from drying up. Let cool.

(B) CONVENTIONAL – Dough Kneading

• Add all ingredients (except butter) into breadmaker; first the wet ingredients, then followed by the dry ingredients.
• Select "dough" mode and let knead until all ingredients come together, usually I let it knead for approximately 8-9 minutes.
• Then add in the butter, continue kneading until the dough is smooth and elastic. The time of kneading in the breadmaker should take approximately 20-25 minutes. For those using standmixer, upon 15-20 minutes of knead time, check to see if dough has achieved windowpane stage.
• Remove dough and transfer to pastry mat. Portion out 180g of dough and place back into mixing bowl. Add chocolate paste into mixing bowl and knead 3-4 minutes until well incorporated.
• Transfer chocolate dough to pastry mat and shape both doughs into smooth, round balls. Let proof in a warm place covered loosely with cling wrap or damp towel until doubled in size (approx. 45-60 minutes). 
  

Dough Shaping

• Grease hands lightly with neutral flavoured oil or butter, then punch down both orange and chocolate dough to deflate. Divide orange dough into 10-12 uneven portions with 2 portions being slightly bigger - these will be the top and bottom layers. Divide charcoal dough into 10-11 portions. To pre-shape, roll each portion into a round, even ball then let sit on bench to rest for 15 minutes, covered with cling wrap or damp towel.
  
• To shape the stripes, we would layer the dough alternately with the orange and chocolate dough. Start with a larger orange dough as the first layer - flatten with rolling pin and place aside. Next, roll out a chocolate dough, placing it towards the side, atop of the orange dough.
  
• Top with another orange dough, and repeat with stacking another chocolate dough on the other end to create a zig zag layer.
  
• For some layers, I suggest rolling out a chocolate dough, slicing it into half through the middle, placing one on each side, atop an orange dough.
  
• Repeat for remaining dough, ending with the other larger orange dough then arrange evenly in tin. Cover and let rise for 40 minutes or until 80% to the rim. During last 15-20 minutes, preheat oven to 190°C.
  
• For square-shaped loaf, put the greased lid on and bake on the second rack from bottom at 190°C for 30 minutes, then lower down the temperature to 180°C and bake for a further 5 minutes.
• Remove bread from tin and allow to cool completely on a cooling rack for at least an hour before slicing and serving.