I decided to see if the James Martin cake would convert to low carb. Happy to report it did. I substituted the flour to Ultra fine adding a tsp of baking powder , plus the sugar I used xylitol and coke zero.
Here is a link to James Martin's recipe https://www.cooked.com/uk/James-Martin/Quadrille-Publishing/Desserts/Cakes-and-bakes/Chocolate-cola-cake-recipe
Here is a link to James Martin's recipe https://www.cooked.com/uk/James-Martin/Quadrille-Publishing/Desserts/Cakes-and-bakes/Chocolate-cola-cake-recipe