Preheat oven to 180° C and prepare baking time.

Sieve the dry ingredients (flour, cocoa, salt, baking soda) in a bowl. Mix and set aside

In a separate bowl, mix butter and sugar until well combined

Add in the eggs one at a time

Add the vegetable oil; beat until the oil is incorporated into the mixure

Add white vinegar and vanilla extract and beat

Add buttermilk and beat until the mixture has a smooth consistency

Incorporate the flour mixture little by little until all the flour is well mixed in to the mixture

Gradually add the food coloring as you beat the mixture

Put the batter into the baking tin and put in the oven. Bake for 30 minutes until a toothpick inserted in the middle comes out clean