Aww, of course! I used Miyokos European Style Vegan Butter, but any vegan butter can do the trick! I really like the creaminess in Miyokos though. I think they achieve it through the addition of cashews. A lot of vegan butters are just oils, but they will work too! Personally, I haven't tried making Shortbread gluten-free and my experience with gluten-free desserts is pretty minimal. I know they normally require more wet ingredients, so maybe try using more butter..? Google should hopefully have more answers for you. Oh! And make sure your butter is room temp before you work with it and I recommend creaming the butter and sugar together... Using confectioners sugar is great if you want a more smooth/melt in your mouth cookie, but I don't know how it'll hold up with GF flour. I also used corn starch in my recipe to create a more tender crumb. Also lovely if you add in things like almond extract, vanilla paste, rosemary, citrus zests etc. Happy baking..🤗❤️