Yes, this is exactly what it looks like: a giant nut butter cup that rivals anything you’d find at the store. Actually, it’s better, because the filling—made with hazelnuts here—is faintly crumbly, just like the original, and crispy-crunchy thanks to the addition of crushed-up ice cream cones. You could use a knife dipped in hot water and wiped clean to cut the tart into neat slices, but joyously hacking into it with abandon is more in keeping with the holiday spirit.
Hazelnuts feel festive and apropos of the holidays but peanuts or pecans (my personal favorite) are excellent swaps. Toast them as you would the hazelnuts.