First, sift the all-purpose flour into a bowl. Next, add the baking powder and mix well.
Next, break three eggs into a large mixing bowl and add the sugar. Beat the mixture until it becomes light, frothy and pale in colour. After that, add the vanilla essence and mix briefly.
Now, gradually add the flour mixture, a little at a time, to the beaten egg mixture. Using a spatula, gently fold the flour into the batter until it is fully incorporated.
Heat the milk and butter together in a microwave or on the stovetop until the butter melts and the mixture is hot. Stir well to combine. Then, carefully pour the hot milk and butter mixture into the cake batter.
Line a 6-inch cake tin with baking paper. Pour the prepared batter into the tin and gently tap it on the counter a few times to release any large air bubbles.
Place the cake tin in the preheated oven and bake at 170°C for approximately 30–35 minutes.
Once baked, remove the cake from the oven and allow it to cool in the tin. After it has cooled completely, carefully unmould the cake and slice it.