Combine the flour, sugar, xanthan gum, salt, spices, orange zest, yeast and buttermilk powder in the bowl of a food processor. Pulse once or twice to mix all the ingredients.
Add the butter cubes and pulse a few times to get a fine mixture of butter and flour.
Add the eggs and egg yolk along with 1/3 of the warm water. Mix gently until well combined. Leave the mixture to sit for 5- 10 minutes.
Meanwhile, prepare 12 muffin cups by lining with tulip muffin liners or greasing well with butter.
Mix the dough again adding another 1/3 of water. You can mix in the food processor or by hand. Leave the dough to stand a further 5- 10 minutes. While the dough is resting, drain the liquid from the sultanas.
Add the remaining water to the dough and mix again. The dough will be the texture of a cake batter and should reluctantly drop from a spoon. Add the drained sultanas and mix through the batter.
Using a spoon or a measuring cup dipped in cold water, place a dollop of mixture into your prepared tins. Don't fill the tins more then half way as you will need to leave some room for them to expand. Cover the muffin tin loosely with cling film. Leave somewhere warm and cozy for about 1 hour.
Preheat oven to 200 C
Whilst the buns are proofing, make the flour and water paste by mixing a little water into some Doves farm plain flour. See note below. If you are using an icing sugar cross, which goes on the buns after they come out of the oven, you can make this now.
To prepare the sugar syrup combine the sugar and water in a pan. Bring the water to a simmerinng boil and then leave it to simmer for about 4 minutes until the mixture is a bit syrupy. Leave to cool.
When the buns have risen to about double their original size, they are ready to bake. If you are using the traditional flour paste to make a cross, then pipe this onto the buns just before they go into the oven.
Make sure the oven is hot. Place the buns in the oven and bake for 30 minutes. Don't open the oven door but keep a watchful eye that the tops of the buns don't colour too quickly. If this is happening, place a sheet of tin foil loosely over the top of the tin and close the oven door quickly.
Remove the buns from the oven and leave to sit for a few minutes. Brush with the sugar syrup glaze.
If you are using the icing sugar paste, (see note below) pipe this onto the buns once they are cool.
A Note about Crosses
I've tried a few different methods and I'm giving you two suggestions. I prefer the icing sugar crosses, but if you want the more traditional approach this will work too.
To make the traditional cross: Combine 50g Doves Farm Flour and a little water. It should be fairly stiff and not at all runny. Place this in a piping bag and pipe onto the buns just BEFORE you put them in the oven.
To make icing sugar cross: Combine 100g icing sugar with the juice of 1/2 orange. Mix until you have a stiff mixture. Place this in a piping bag and pipe onto the buns AFTER they are out of the oven. Best to leave the buns cool before piping on the crosses.
The success of this recipe depends on leaving the dough to rest in between mixes and adding the water in stages. It takes a little extra time but I guarantee it's worth it.