Preheat the oven to 200 degrees C. Prepare a 12 hole muffin tin by lining it with muffin cases.
Put the dry ingredients into a large bowl. Put the wet ingredients into a jug and whisk together, then tip into the bowl. Stir together until it’s all combined.
Crumble the feta into the bowl, making sure that none of the pieces are bigger than 1cm square. Stir again to make sure they’re evenly distributed through the mix.
Spoon the batter evenly into the muffin cases. Sprinkle the top of each one with grated Parmesan.
Put in the oven for 15-20 minutes, until risen, golden and cooked through.