Preheat the oven to 180C | Gas Mark 4.
Line a loaf pan with baking parchment and set aside.
In a large mixing bowl, combine both the flours, sugar, baking powder and salt. Make a well in the middle of the dry ingredients and add the milk, oil and vanilla extract. Stir until combined.
Transfer the batter into the tin. Bake in the middle of the oven for 50 minutes or until a skewer inserted in the middle of the cake comes out clean. Let the cake cool at least 15 minutes in the loaf tin before turning it onto a wire rack. Let the cake cool completely before decorating.
