Preheat the oven to 200c/400f. Brush or spray a 12 hole, deep muffin tray with oil.
Add the oil, melted butter, egg and buttermilk to a bowl. Mix using a fork or balloon whisk.
Add in the flour, baking powder, bicarbonate of soda, all but 3 tbsp of the Grana Padano, salt, garlic salt, parsley, and Prosciutto di San Daniele. Mix together using a wooden spoon until just combined (don’t over-stir or the muffins will be tough)
Take the prepared muffin tine and add one tablespoon of the muffin mixture to each of the holes. Place an egg on top, in each of the holes, and top with the remaining muffin mixture. Push the muffin mixture down the sides and around the egg using a spoon. Sprinkle on the reserved cheese and place in the oven. Cook at 200c/400f for 5 minutes, then turn the oven down to 175c/350f and cook for a further 12-14 minutes – until the tops are golden brown.
Once cooked, leave to cool in the tin for 10 minutes before removing.
Eat warm or cold alongside some extra Prosciutto di San Daniele!