Apple cider cake layers with shortbread frosting, apple pie filling, streusel filling and vanilla bean buttercream.
Spread the clusters on a parchment lined sheet pan. Bake for 20 to 25 minutes, breaking them up occasionally and keeping an eye on them toward the 20 minute mark. The crumbs should be golden brown and still slightly moist to the touch at that point; they will dry and harden as they cool.
Cut in the butter to the flour mixture until small clumps have formed. You can also use your hands to create clusters if you need to.