Place yeast, sugar and 125ml (½ cup) lukewarm water in a bowl and stir to combine. Set aside for 10 minutes or until the mixture bubbles. Add orange juice, zest and 2 tbsp oil, and stir to combine. Place flour and a pinch of salt in a large bowl and make a well in the centre. Pour yeast mixture into the well and stir until combined. Turn dough out onto a lightly floured work surface and knead for 5 minutes or until smooth and elastic. (Alternatively, use an electric mixer fitted with a dough hook.) Place dough in a greased bowl and cover with plastic wrap. Set aside in a warm, draught-free place for 2 hours or until dough doubles in size.
Meanwhile, to make honey syrup, place lemon juice, sugar and 250ml (1 cup) water in a pan over medium heat and stir until sugar dissolves. Increase heat to high and bring to the boil. Add honey and orange-blossom water, if using, then reduce the heat to low–medium and cook mixture for 35 minutes or until the consistency of runny honey; watch syrup to make sure it doesn’t boil over. Transfer to a large bowl and cool.
Fill a deep-fryer or large pan one-third full with oil and heat over medium heat to 180°C (or until a cube of bread turns golden in 15 seconds). Working in batches, tear off a piece of dough about the size of a plum and flatten slightly with your hand. Tear a hole in the middle and stretch dough to make a 12–15cm ring. Gently drop dough into oil and deep-fry, turning halfway, for 4 minutes or until crisp, golden and cooked through. Remove with a slotted spoon and drain on paper towel.
Using a skewer, pierce yo-yo on both sides, then soak in honey syrup for 4 minutes each side. Serve immediately.
* Orange-blossom water is available from delis and Middle Eastern food shops.