• Preheat your oven to 180˚C / 356˚F (fan forced).

For the homemade buttermilk (skip if using 1 cup Greek yoghurt)

• Place the milk in a small bowl and add the lemon juice (or white vinegar). Stir gently then set aside for a few minutes to curdle.
  1/2 cup milk, 3/4 tbsp lemon juice

For the cake

• Place the softened / partially melted salted butter in a large mixing bowl or the bowl of a stand mixer. Add the caster sugar and cream together until the mixture turns pale yellow and fluffy, around 3-5 minutes. Tip: Scrape down the sides as you go if needed.
  ½ cup salted butter, 1 ¼ cups caster sugar
• Crack in the eggs, one at a time, mixing well each time until they’re evenly blended into the batter.
  3 eggs
• Pour in the homemade buttermilk, olive oil and lemon zest. Stir in until just combined. Note: The batter will look a bit lumpy or curdled at this stage, but don’t worry - this is what you want.
  4 tbsp olive oil, zest from 1 large lemon
• If using a stand mixer, fold in by hand from here. Add the polenta and fold through until combined.
  1 cup fine polenta / yellow fine cornmeal
• Add the self raising flour and baking powder and fold through again until the batter is smooth.
  1 ½ cups self raising flour, 1 tsp baking powder
• Pour batter into a round springform cake tin (greased or lined with baking paper). Bake for 45 minutes, then test with a skewer. If it comes out clean, it’s done! If not, pop it back in for another 2-3 minutes and test again. Optional: Place a sheet of aluminium foil over the top at the 30 minute mark to avoid the top going too dark.

For the optional lemon glaze

• Place the icing sugar in a mixing bowl and add lemon juice. Whisk until smooth and slightly runny. Note: For a runnier glaze, add a little more lemon juice. For a thicker glaze, add a little more icing sugar.
  1 cup icing sugar / powdered sugar, 1 ½ tbsp lemon juice
• Pour the lemon glaze over the cake and spread out to evenly coat the surface.