In a large mixing bowl, add flour, yeast, sugar, mixed spice, cinnamon, nutmeg, clove and salt. Mix with a wooden spoon until well combined. Set aside.
In a small pot, add milk and butter, place over a low-medium heat until warmed through, stirring to combine. Test it by dipping in your finger, you should not get burnt/scalded. Remove from heat.
Make a well in the centre of your dry mixture. Pour in warmed milk mixture followed by the whisked egg. Using a wooden spoon, gently stir flour into liquid, mixing until it begins to form a dough.
Before forming into a ball of dough, add sultanas, mixed peel (if using) and orange zest. Using your hands, mix the fruit into the dough.
Turn dough out onto a lightly floured surface. Knead dough for 8 minutes until smooth and springy.
Take a large mixing bowl and lightly grease it with olive oil or butter.
Place dough into greased bowl, cover bowl with a tea towel and place in a warm, draught free area for 1 hour or 1 hour and 15 minutes until dough has doubled in size.
Punch down dough with your fist to deflate. Turn out onto a lightly floured surface and lightly knead for 30 seconds or until smooth.
Line a large baking tray with parchment paper, set aside.
Divide dough into 12 equal pieces TIP: weigh the entire piece of dough and divide that total weight by 12, leaving you with the weight needed for each individual dough ball.
Roll each piece into a smooth ball. Place on lined tray in 4 rows of 3, slightly touching each other.
Cover with a tea towel and place in a warm, draught free area for 30 minutes until risen slightly.
Whilst buns are rising, pre-heat oven to 190ºC fan-forced (375ºF fan-forced).
Crosses
In a mixing bowl, add flour and 6 tablespoons water. Mix to combine, adding extra water if needed to turn mixture into a thick paste.
Prepare a piping bag fitted with a small round piping tip. Pour flour paste into bag.
Pipe crosses onto buns.
Bake for 15-20 minutes until lightly golden all over and they spring back when touched.
Make glaze whilst buns are baking.
Glaze
In a mixing bowl, combine icing sugar, cinnamon, all spice and 2 tablespoons orange juice. Mix to combine to a thick liquid glaze, adding extra tablespoon orange juice if needed to thin it out.
Remove buns from oven and using a pastry brush, generously brush glaze over each warm bun.
Cool on pan for 10 minutes and allow glaze to set.
Serve warm with a spread of butter or allow to cool completely and serve later.
Notes
Store in an airtight container, in the pantry or refrigerated, for 2-3 days. Best served freshly baked!