re: White Chocolate Mud Cake Recipe

Hi, made this just yesterday and tasted fab although it gave a 4cm cake (with crust top in tact) and it was so doughy inside I couldn’t really use it for a wedding cake as it looked raw (it was cooked for an extra 15 mins too) any suggestions what I have done wrong? Been baking for years now and never had this prob, is it supposed to look like that? Cheers x