To prepare the cake mixture in the food processor: place the room temperature butter, sugar, flour, baking powder and salt into the bowl of the food processor. Pulse a few times until the ingredients are combined. Add the eggs one by one, and pulse 1-3 times after each egg. Finish by adding the milk and vanilla seeds and process until just combined. Take care not to overmix the batter.
280 g unsalted butter, 280 g golden caster sugar, 280 g all purpose flour, 2 ¼ teaspoons baking powder, 5 eggs, 60 ml milk, ½ vanilla pod, ½ teaspoon fine sea salt