The Black and White Cookie test

I used to go to NYC back in college (it was a 2-hour train ride away) and I loved to get black and white cookies. I moved out to Ohio 10+ years ago and haven't had an authentic black and white cookie since. So, when my sister's bridal shower came around this past May, I asked my mother in law (who is an awesome baker and cook) to make a batch as favors. She did and they were incredible-light, fluffy lemony cookie with a sweet frosting.

So today I was excited to find them at Costco, as I haven't seen them in any bakery or store around here. I just tried the version Costco sells, as pictured above. Sorry Costco, they don't compare to my mother in law's (or the ones in NYC!)