De or het rumpudding?

The correct Dutch article is:

de rumpudding

Rule Words ending in -ing: almost always de. See the rule

How to use rumpudding

the rumpuddingde rumpudding
this rumpuddingdeze rumpudding
that rumpuddingdie rumpudding
our rumpuddingonze rumpudding
your rumpuddingjouw rumpudding
every rumpuddingelke rumpudding
which rumpudding?welke rumpudding?
a big rumpudding / the big rumpuddingeen grote rumpudding, de grote rumpudding