Mix the brown sugar and cinnamon together and set aside

Cream the granulated sugar and sunflower spread together until light and fluffy, then mix in the vanilla extract

Add in the milk and apple puree then sift in the flour, baking soda and xanthan gum if using together, stirring into the creamed mixture until just combined

Pour half of the batter into the loaf tin and spoon a line of the cinnamon sugar down the centre

Use the end of the spoon or a clean finger to gently swirl the cinnamon mixture around a little

Now evenly spread half of the diced apple on top and pat in slightly

Pour the rest of the batter on top of the apple layer

Repeat the cinnamon sugar line and swirl it, then gently pat the last of the apple into the top of the cake. Save a pinch of the cinnamon mixture for sprinkling over the very top

Bake for 70 minutes, the top should be caramelized and the cake pulled in from the edges of the tin