Preheat the oven to 110C/90C Fan/Gas ¼ (this will be to keep the pancakes warm as they are cooked in batches).
Put the flour, sugar, baking powder, cinnamon, ginger and salt into a large bowl, give them a quick mix and make a well in the centre. Finely grate the lemon zest in, if using. Split the vanilla pod open, scrape the seeds out and add them, too (or vanilla extract). Then gradually pour the milk in bit by bit, stirring all the time to give a smooth mixture. Then beat the egg in well and set aside.
Put a drizzle of oil into a large frying pan on a medium heat and cook the Parma ham for 2-3 minutes on each side until nice and crisp. Then remove with tongs and drain on kitchen paper. Keep the ham warm in the oven until ready to serve.
Leave the pan on the heat, but reduce the heat to low and add a little bit more oil if need be. Then spoon in four dollops of the pancake mix (to spread to about 10cm/3¼in wide). Leave to cook for about 1-2 minutes until golden, then flip them over and cook for another 1-2 minutes. Slide them onto a baking tray and put in the oven to keep warm. Then, repeat with the remaining mix to make about 12.
Once you have made all of the pancakes, divide them between four plates. I like to pile the parma ham high on them and then drizzle with the maple syrup and serve with a dollop of sour cream or crème frâiche.