Preheat the oven to 160C/325F and spray a 2lb loaf tin with cooking spray. Place a thin strip of grease proof paper along the centre to lift the cake out.
Place the butter, sugar and lemon zest into a large bowl, or the bowl of your stand mixer and beat on medium-high speed until light and fluffy, around 2 minutes.
Add in the eggs, scraping down the sides as necessary and mix on medium speed for 1 minute, or until well combined and smooth.
Add in the flour, baking powder, bicarb, salt and desiccated coconut and mix on low until the mixture starts to come together, then add in the coconut milk. Turn the speed up to medium-high and mix until everything is light, smooth and well combined.
Spoon the batter into your prepared loaf cake and spread into an even layer. Place in the oven for 60-70 minutes, until risen, golden and an inserted skewer into the centre comes out clean.
Leave to cool completely before transferring the cake to a cutting board. Place the desiccated coconut into a frying pan over a low heat and stir frequently until all the coconut is golden brown. Leave to cool.
Sift the the icing/powdered sugar into a medium sized bowl and add in the coconut milk, whisk until smooth and thick. You want a thick paste that you can spread, but won't run everywhere when you place it on the cake.
Spoon the icing onto the top of the cake and spread with a small angled spatula until you've covered the top in an even layer of icing.
Spoon the toasted coconut onto the icing; you should have enough to completely cover the icing.
The icing will set a little if you leave it out, you can wait for this to happen before serving or serve straight away. Cut into 10-12 slices and dig in!
Lemon and Coconut Loaf Cake will keep in an airtight container, at room temperature, for 4 days.