Combine flour, sugar, yeast, cinnamon, mixed spice, ginger, nutmeg, salt and cloves in the bowl of a stand mixer (or any large bowl).
Add the milk, butter, egg, vinegar, sultanas and mixed peel. Using the dough hook attachment of a stand mixer or handheld electric mixer, knead until smooth but still a little sticky (about 8 minutes).
Divide dough evenly into 12 pieces. Using lightly oiled hands, roll each piece into a ball and place 1-2cm apart on a large baking paper-lined oven tray or roasting dish. Cover with a piece of oiled cling film and leave to rise in a warm place until almost doubled in size (about 1 hour).
Meanwhile, make the cross paste by mixing the flour, baking powder and water together.
Transfer to a piping bag.
Bring the sugar and water to a boil in a small saucepan. When the sugar has dissolved, remove it from heat.