Preheat the oven to 180 degrees (fan oven) then grease and line a 9 inch, round (or heart shape!) cake tin
Place the wet ingredients into a jug and set aside
Put the dry ingredients into a food processor, switch it on then pour in the wet ingredients and let it run for a minute or so until all the ingredients are well combined
Pour the cake mix into the prepared cake tin and bake for 35-45 minutes (insert a skewer into the centre of the cake to check if it's cooked through - it should come out clean)
Allow the cake to cool completely on a wire rack
Use a hand mixer to make the chocolate butter icing by creaming together the softened butter and icing sugar then beat in the melted chocolate
Cover the cake with a layer of icing then serve
Recipe by Cook Low FODMAP at https://cooklowfodmap.com/low-fodmap-chocolate-celebration-cake/