As in imitation maple-flavored corn syrup? I wouldn’t expect that to work very well. I’ve never tried making my own stroopwafels, but I’ve been poking around the interwebs. It seems the Dutch have something they call keukenstroop (literally “kitchen syrup”), which is what they put on pancakes. As far as I can tell it seems to be similar to Lyle’s Golden Syrup but darker. Perhaps a mixture of Golden Syrup with Lyle’s Black Treacle or Molasses would work. You can buy Golden Syrup at larger grocery stores, often in the international aisle (it’s a British product). Good luck finding keukenstroop over here though.