
Add warm milk, water, one tablespoon of brown sugar and yeast in a large mixing bowl or the bowl of your stand mixer. Leave the yeast to activate for 2 minutes.
In another bowl, mix the melted butter and remaining brown sugar together. Beat in the egg, then add the salt, cinnamon, mixed spice, vanilla and sultanas.
Mix the yeast and spice mixture together along with the remaining flour. Knead the dough by hand for 10 minutes.
Divide the dough into pieces and shape them into small balls. Leave them to rise for 30 minutes to an hour.
Mix the flour and water for the crosses and pipe the mixture onto the buns. Bake for 15-20 minutes.
Brush the tops with maple syrup glaze after baking.