Grease and line a brownie pan. Mine is a 20 cm (8 inch) square pan, but you may need a smaller baking tin depending on your air fryer size.
In a pan melt the vegan butter, golden syrup and brown sugar. Once melted set aside.
Measure the oats and salt into a mixing bowl and mix.
Pour the wet ingredients in and mix well until the oats are completely coated.
Pour the flapjack mixture into the pan and press down firmly to make as even a layer as you can.
Air fry at 180°C/350°F for 20–25 minutes, or until the edges are golden and the centre is set but still slightly soft. Don't overbake if you want chewy flapjacks.
Remove from the air fryer and leave to cool in the pan.
Once cool, you can carefully remove the block from the pan and cut into 16 bars or you could cut into 25 smaller bites.
Notes
Your air fryer might not be big enough to hold a brownie pan, do measure first to see if one will fit, it not look for one or two smaller pans.
My air fryer has shelves, if yours does not, then pop something underneath the pan, when you pop it in the drawer to raise it off the bottom.
The flapjacks can be kept in a cake tin or airtight container for up to a week. I like to wrap them in baking paper.
To oven cook, preheat your oven (same temperature), but check on it after 20 minutes and keep an eye on the flapjacks so they don't brown too much.