Preheat the oven to 180°C/375°F or 160°C/320°F for a fan oven.
Prepare a small panibois or a loaf pan (11cm x 17.5cm) by buttering and lining the tin base with a rectangle of parchment paper.
In a bowl, mix the flour, baking powder, and salt. Set aside.
In another bowl, beat the egg with sugar using a balloon whisk until light and fluffy.
Add the oil, vanilla, and lemon essence, and stir well.
Using a wooden spoon or spatula, fold the dry ingredients into the mixture until well combined. Then, add the milk and mix until fully incorporated into the batter.
Bake in the preheated oven for 25 to 30 minutes, or until a skewer or cake tester comes out clean.
Once baked, remove the cake from the oven and let it cool. Then, remove it from the tin and place it on a cooling rack.
Enjoy with a cup of coffee or tea!