Mix flour, sugar, spices, and lemon zest in a large bowl.
Add salt and yeast to opposite sides of the bowl.
Melt butter and warm the milk in separate pans.
Combine the butter, half the milk, and the egg with the dry ingredients.
Gradually incorporate remaining milk to form a soft, pliable dough.
Knead dough on a floured surface for 10 minutes while incorporating sultanas and mixed peel.
Place dough in an oiled bowl, cover, and let rise for 1.5 hours until doubled.
Divide dough into 12 balls and place on lined baking trays.
Cover trays with polythene bags and prove for 40-60 minutes.
Preheat oven to 220°C.
Mix 75g flour with 100ml water to create a topping paste.
Pipe a cross onto each bun and bake for 15-20 minutes until golden.
Brush warm buns with melted golden syrup and cool on a wire rack.