Pre-Heat the oven to 350F and spray and line the loaf tin with parchment paper.
First mix together the flour, baking powder and salt in a small bowl. Set that to the side. In another small bowl combine the milk, kalamansi juice and vanilla essence. Note it will start to curdle because of the milk and kalamansi juice sitting together. Don’t worry! It will come back together in the batter.
Next cream together the sugar and butter until light in color and fluffy. Add the eggs after incorporating one at a time. Scrape down the bowl and whisk in the milk mixture and mix until there are no lumps. Finally add in the flour mixture and fold in lightly until you don’t see any more flour.
Pour the batter into the prepared loaf tin and bake for 45-50 minutes. To check if the loaf is fully baked stick a long skewer down the middle. If there is still uncooked batter on the stick when you pull it out, keep baking in 5 minute increments until the skewer is nice and clean when you check it.
Take the loaf out of the oven and leave to cool in the tin for 10 minutes and then unmold and cool on a wire rack fully.