I always have a hard time finding these things locally:

• malt vinegar powder and liquid (not Sarsons… I know where to get that and there is nothing wrong with it but just want to try something different)
• steel cut oats (sometimes called Irish oatmeal but I’ve seen the standard rolled oats also called Irish and that’s not what I’m after)
• Liquid Smoke
• Flipperzero (unlikely on any shelves, but worth asking)
• Bus Pirate
• Mongolian Fire Oil – not sure if there is a generic name for this stuff but it’s a kind of spicy hot oil with a quite unique character

Any shops in Amsterdam worth a look?