This pack has a BBE date of April 2023, but I have checked and there is no clumping or hardening.
Extra Dark Spraymalt is simply spray drIed liquid malt extract and is used instead of sugar to add body to beer kits or can be used instead of liquid malt extract when brewing beer using your own recipes. It will darken your beer kit and will produce a richer flavour. Unless you are specifically trying to darken your beer dramatically, it should really only be used with porters and stouts.
If using instead of liquid malt in extract brewing, you should bear in mind that spraymalt is more concentrated than liquid malt extract and that you should thus use around 20% less then the amount of liquid extract specified in the recipe.