You will need tall mounts. I think that is what I have on a Nova Vista Freedom (basically same gun as Aspen) with a Hatsan Optima 4-12x50. Sorry, I don't remember for sure and these mounts are probably cheap, but I don't remember the brand either.
Here here are some pics if that helps. Sorry for the quality. My flip phone camera sucks.
The space between the 1 inch scope tube and the mounting rail is ~1 inch.
They *may* be UTG, but I really don't remember. Maybe the pics will help?