I'd made cookies with mint before, but for these I decided to strain out the mint leaves this time(cookies on left), though I then used the refuse leaves to make some more cookies (cookies on right)

I used a 1-cup-of-butter shortbread recipe with about 0.3 pounds of mint leaves. I think the mint flavor is weaker after doing the oil infusion rather than just chopping them up and putting them in the cookies, perhaps I did the infusion too long, though and some of the flavor chemicals were volatile. Anyway, I filtered the butter through a mesh collander, and mixed it with the shortbread mix. The refuse mint leaves, I mixed them into a chocalate chip recipe. Aside from the fact that I made up the recipe and they ended up being more like overmixed scones, they also tasted nice and minty. Here's some more pictures if you want.