Not sure if this counts as a recipe request, so sorry if I'm posting in the wrong place!

https://preview.redd.it/uw7a511cj28d1.png?width=600&format=png&auto=webp&s=bf02adbb7062ec3595d94a860c8cc8540b556421

I got some cookies from Italy like the one above. The image is from https://lazzaronibiscotti.it/biscotti-lazzaroni-2/pangoli-con-crema-al-limone/ but the brand I tried had a lemon cookie, as well as two with chocolate cream, and one with a hazelnut cream inside, which was the best.

The cookie shell is hard and crunchy, but the filling, especially the hazelnut one, has a very light and fluffy texture, almost like a pastry cream folded with whipped cream, or maybe something like a creme mousseline?

Googling cookies with cream fillings just leads me to sandwich cookies which is not what I'm looking for. This video I found is kind of the right idea, but the filling here is more of a lemon curd, and when he breaks it at the end you can see the cookie is still quite soft.

How can I go about recreating this? I can't imagine piping cream into a hard cookie, but it also feels like baked pastry cream wouldn't give the right texture for the filling. Does anyone have ideas on how to go about this, or a name for this style of cookie that would help in my googling?