I've been to the Dakkas four times and every time it's been excellent. The food is great and very tasty, and they are ready to adapt to your dietary requirements, if any (one of my lunch companions needed to eat gluten free, and that was no problem at all). The only thing, the last time I was there the food was very cold, as if it had just been taken out of the fridge, but for the rest everything lovely with plenty of choice, mainly vegetarian but there are also some meat and fish options. Good beers and a very nice choice of original, non standard drinks too. Their coffee is also quite good. I've had the best tomato juice ever and my cappuccino wasn't more expensive because of the fact that I asked for oat milk, which is definitely a plus since everybody else makes it more pricey for that reasons. Plus I loved the fact that tea leaves come loose in a reusable metal sieve so that there are no throw-away teabags and no microplastics, everything is environmentally sound and better for your health. The view is amazing and the terrace in Summer is a wonderful place to have lunch or dinner. Another plus: lovely personnel. And as a little, thoughtful finishing touch: a card with digestive peppermint candy after your meal.
You won't know there's such a nice restaurant from street level, since it's on top of a big vertical parking lot with practically no signs that give away its location. De Dakkas is Haarlem's best kept secret, though people who live in Haarlem know it very well (it's always pretty full). :)