Baking – How to create fruity or grassy shortbread cookies

I saw a recipe for green tea shortbread cookies with white ganache filling and fell in love with it. But here, it is quite hard to get any matcha, the few Amazon marketplace sellers have very high prices.

Now I want to use this as an inspiration to create a new recipe. I want to have a shortbread cookie which has a light, summery flavor added to the dough. As I can't get matcha, I don't think I can do something else from the grassy corner, but a fruity taste would be good enough.

The problem is that this recipe works because the matcha is a dry powder. I know of other recipes which include a dry powder, such as mandelkipferl, but I can't think of a fruity powder to use. And I am afraid that adding fruit-based ingredients will make the dough too liquid. My current best idea is to proceed like making raspberry leather, but after I have reduced the strained raspberry juice, to add it to the dough instead of letting it dry. I am not sure if it will work.

My questions:

• Do you think the raspberry idea will work, and why (or why not)?
• If you think that raspberries will work, what is the best form of incorporating them? How to get the product as dry as possible without it hardening?
• How much raspberry juice/syrup can I add before it changes the dough too much?
• How should I change my dough working methods after the addition of raspberry juice/syrup?
• Can you think of any other method which will give me a fruity or grassy tasting cookie dough?

My constraints:

• The taste should be incorporated in the dough itself. Not in the filling, and not be present as chunks in the dough (the way scones have raisins, etc.).
• The taste should be of summer fruit or herb(s). Not maple, almond, nutmeg, chocolate, etc. – I know these are easy to incorporate, but it is not what I want to do right now.
• The taste should come from the plant itself. I know I can get powder intended for flavoring water or milk, consisting of dextrose and synthetic aromas, but I don't want that.
• The taste should pair well with the white chocolate ganache.
• I don't insist on keeping the texture absolutely the same as a shortbread cookie. After all, I will be adding wet ingredients where there were none. But I still want it to be close enough to be recognized as a shortbread derivative, I don't want to create a baked pancake or a chewy cookie, or something else.