Translation:I hope that that berry is delicious.
I agree completely. They are teaching us "että", but then if I was writing something like that, I would definitely avoid having the same word, even if with a different meaning, used twice in a row. Would even prefer not to have that in one sentence. Maybe the creators can rephrase both sentences, like use "tämä marjä" instead. Or just drop että and one of the that's.