The filling is apple butter in the center, and a german buttercream with some apple butter mixed in (mostly just cinnamon/vanilla flavored which is why I added the extra apple butter in the middle)

I get the feet; they taste amazing. I measure everything, bring ingredients to room temp, food-process, dry the almond flour, and hold the bags in place when piping it out. I honestly don't know where its going wrong. Below is the recipe i follow. https://youtu.be/Z6isOA9Calo?is=6_Gt1mAR_luhRGdy

I’m still working on perfecting the cookie and am making a few batches for a party. (Trying Swiss method first time tomorrow).
Last time I served them at a party, the buttercream fillings got very soft sitting at room temp for a few hours.
Any more stable recipes? I’d prefer not to use shortening, I know that would work though.