Grease baking tin with butter and line with baking paper.

In a bowl, whisk the oil, muscovado sugar and eggs together until smooth and there are no lumps of sugar. Sift over the flour, bicarbonate of soda, baking powder, ground cinnamon and ground cloves and add the orange zest and a pinch of salt. Whisk until evenly combined, then fold through the carrots. Pour into the prepared tray and smooth into the corners.

Bake on the middle shelf of the oven for 35-45 minutes until golden. Leave to cool in the tin for 10 minutes, then transfer to a wire rack to cool completely.

To make the frosting, beat the butter and half the orange zest using an electric whisk until soft and creamy. Sift over the icing sugar and beat for 2-3 minutes until evenly combined. Beat in the cold soft cheese for 3-4 minutes until fully light and fluffy.

Spread the frosting over the cooled cake and sprinkle over the remaining orange zest to serve.