Preheat oven to 180 C / 350 F (160 fan forced). Line an 8-inch square baking tin with parchment paper and grease sides with oil. If an 8-inch square baking pan isn’t available, you can use a 7-inch square pan, or an 8-inch round pan.
Sift flour, baking powder and salt together in a medium sized bowl.
In a large bowl, cream butter and sugar together until fluffy and pale in colour. This can be done with a wire whisk or an electric hand mixer.
Add eggs one at a time, whisking after each addition. If using an electric hand mixer, whisk for about 20 seconds, and is using a regular whisk, mix until combined. Once the eggs have been added, mix in the vanilla essence.
Add the flour mixture, and fold through with a spatula. Add the food colour (if using), and gently fold it through.
Pour the cake batter into the prepared greased pan. Bake for 30 – 35 minutes, or until a toothpick or skewer inserted in the centre of the cake comes out clean.
Let the cake sit in the tin for around 10 minutes, and then turn it into a cooling rack to cool completely. Place the cooled cake on a chopping board and use a sharp knife to cut the cake down the middle, and then into ¼ inch strips. These strips can then be cut into smaller cake strips.