The crank bolt looks like it could be meant to be a self extracting type. Did you perhaps remove a ring that filled out the gap between the hex head and the crankarm first?

If it was me, I'd try with a regular crank extractor (for square taper) first. Maybe need to use some sort of washer to get the plunger to engage the BB spindle properly. Or swing by your lbs and ask for a self extracting crank bolt ring.

Or a generic 2-arm gear/bearing puller (any car nut will have one) can be used. Arms hook between crank and BB, plunger engages the BB spindle. Make sure the plunger pushes on the spindle, and not on the ledge inside the crankarm.