Knead together all of the dough ingredients except the butter, fruit and zest. Knead by hand or using a machine. Add the butter last and knead to a soft, smooth and elastic dough. Cover loosely and allow the dough to rise, until it's puffy (though not necessarily doubled in bulk).
Soak the dried fruit in hot water or hot orange juice to soften. Drain before adding to the dough in the following step.
Gently deflate the dough, and knead in the fruits and zest. Shape the dough into a ball and place it in a panettone mould or other straight-sided round cake tin. Remember to line the bottom and sides with baking parchment so the sides are taller than the sides of the pan. Cover the pan and let the dough rise until it's just crested over the rim of the pan. This should take about an hour or so.
Divide the dough equally into about 10 portions if making Mini Panetonne. Shape each portion of dough into a smooth ball and drop into greased moulds. Allow to rise till the dough just crests the rim of the moulds. Brush the tops with milk.
Bake at 200C (400F) 10 minutes; reduce the oven heat to then reduce the heat to 180C (350F) and bake for 25 to 35 minutes, tenting with aluminum foil if the crust appears to be browning too quickly. Reduce the baking time if baking Mini Panetonne. Panettone should be a deep brown when done, should sound hollow when tapped.
Remove the panettone from the oven and cool completely. If glazing with sugar or melted chocolate, wait until the Panetonne have cooled completely. Store at room temperature, well-wrapped, for up to a week; freeze for longer storage.