Knekkebrød is the Norwegian name for these seed and grain crackers. There are variations out there for gluten free, nut-full or nutfree. In Norway I had one that was homemade but otherwise only store bought (usually Wasa which has made it to the US). I recently remembered the homemade version and how good it was so I had to go to google since we were in a car at the time and I was unable to write down the recipe. I found this recipe about a year ago and it’s so good! Here it is. I included it in my Christmas basket last year. I’ll let google translate the instructions for you but here’s the ingredients list:

Rye (ground)
Rye (whole) or spelt
Oats
Sunflower seeds
Pumpkin seeds
Flax seed
Sesame seeds
Salt
Sparkling water (club soda)

These take a little time to make but they are delicious.

What to put on it? Butter, cheese - Boursin is really good - smoked salmon. Whatever you might put on a cracker.
Nutella was always a favorite for Wasa and would probably be good on these too, though so far I’ve only done savory.