If you can't find (or don't havsome of the ingredients it is OK to leave some out, but make sure you include the cinnamon, cloves, mace, and ginger.
If you only have whole spices at home, you can grind the spices yourself using a coffee grinder, or even a food processor and a fine sieve.
If you need koekkruiden for a recipe, leave out the cloves.
MIX WELL and package into small jar.