Stir treacle and muscovado sugar into 200ml warm water for the dark dough.
Mix flours, cardamom, yeast, salt, olive oil, and sweetened water into a wet, sticky dough.
Knead the dark dough for 8 minutes until elastic and prove for 1 hour until doubled.
Combine orange juice, zest, and enough water to make 200ml total liquid for the orange dough.
Mix flours, yeast, salt, orange liquid, olive oil, and caster sugar into a bowl.
Bring the ingredients together to form a sticky orange dough.
Knead the orange dough for 8 minutes until smooth and elastic.
Cover and prove the orange dough for 1 hour until doubled in size.
Knock back both proved doughs and shape them into rectangles.
Roll both dough types into 30cm x 20cm rectangles.
Cut doughs into 30cm x 10cm pieces and layer them, alternated and brushed with water.
Slice the layered dough block into 12 separate strands.
Roll strands into 20cm sausages and tie them into knots on baking parchment.
Cover the knots and let them prove for another hour.
Preheat your oven to 220°C.
Place two baking trays in the oven to heat up before baking.
Simmer orange juice and muscovado sugar in a pan to create a syrup glaze.
Slide rolls onto hot trays and bake at 220°C for 10 minutes.
Reduce heat to 180°C and bake for 10 more minutes until they sound hollow.
Brush the warm rolls with the orange glaze and serve.