In a small saucepan or in the microwave, warm the orange juice until just simmering. Take it off the heat and stir in the raisins. Leave them to sit and hydrate while the dough is mixed.

Add the yeast, lukewarm milk, remaining sugar, flour, salt, spices, and egg to a stand mixer bowl fitted with a dough hook. Turn the mixer on low speed and combine until it forms a thick but slightly sticky dough. Add in the room temperature butter and keep mixing until the butter has been incorporated.

Turn the mixer to medium speed and keep mixing until the dough strengthens, comes together, and pulls away cleanly from the sides of the bowl. This can take around 10 to 15 minutes. To check if the dough is ready, let it rest for 5 minutes, then grab a small piece and stretch it. Proper gluten development will allow you to stretch the dough so thin you can almost see through it (the windowpane test).

Drain the raisins and add them to the dough along with the orange and lemon zest. Mix on low to incorporate. The raisins will add extra moisture and make the dough sticky again. This is normal. Keep mixing gently until they're evenly distributed.

Pull the dough from the bowl onto a lightly floured surface and form it into a ball. Place it into a clean bowl, cover with a lid, plate, or damp tea towel, and let it rise in a warm spot for 1.5 to 2 hours until doubled in size. For overnight buns, cover the bowl and place it in the refrigerator instead.

After proofing, pull the dough onto a clean bench and divide it into 9 equal pieces (use a kitchen scale for accuracy). Use your hands to form each piece into a tight ball. Line a 9x9-inch square baking dish with parchment paper and place the dough balls inside.

Cover the baking dish with a damp tea towel and let the buns rise until doubled in size. To create a warm spot, preheat your oven to 104°F/40°C, turn it off, then place the buns inside.

Preheat the oven to 350°F/180°C (standard/conventional oven). Mix the flour and water for the crosses into a smooth paste. Scoop it into a piping bag fitted with a small tip and pipe crosses onto the risen buns.

Bake for 25 to 30 minutes until golden brown.

While the buns bake, stir together the sugar and boiling water for the glaze until dissolved. The moment the buns come out of the oven, brush the glaze over the tops with a pastry brush. Let the buns cool for about 20 minutes before eating.