dj. A flap jack is essentially oats butter and syrup, and should be meltingly buttery and syrupy when put in the mouth, which I am sure yours were, all you needed to do if you cut the sugar, was up the butter, A few extras can be stirred into flapjacks; dried, fruit or a few nuts, or even chocolate on top, although some purists would 'tut' over that.
The item the NT want to replace it with sounds delicious but by the time they have added all their extras, it really isn't a flapjack anymore and should not be so described.
Like most people, I only eat the occasional flapjack, so the amount of sugar in it, when added to the amount of sugar I usually eat, is unlikely to exceed any government approved limit.
What the National Trust doesn't seem to understand is that
its cafes are discretionary eating venues and account for an insignificant proportion of its visitors food consumption in a year. Eating in their cafes is a small treat as part of a day out, for most probably less than 6 times a year.
When you go there most people want something, naughty but nice - a scone with lots of jam and cream, a rich cake, or possibly just a nice lunch that is better than a bought sandwich and you do not have to prepare it yourself.
If they tried talking to their visitors, instead of just giving us what they think is good for us, we would all be a lot happier.