I didn’t grow up in a very "decorated cookie" household. My mom hewed more to the biscotti/gingerbread/shortbread crunchy cookie end of the spectrum, and the year I tried to do festively decorated cookies in my own home, I ended up with royal icing in my hair and sprinkles in my floorboards for a week. I took on this fussy baking project in an attempt to impress at a school holiday party. It was my first time trying to border and flood reindeer-shaped gingerbread cookies with contrasting icing hues and dragée eyes, and also my last.
That said, my mom has been making rosemary shortbread cookies during the holidays for about as long as I can recall. I remember having the cookies in the apartment I grew up in on the Upper West Side of Manhattan, and I remember having them after Thanksgiving dinner in the dining room of the apartment where my parents moved after I graduated from college. I know my mom has brought me a box of this shortbread when she's arrived at our annual Christmas Day open house, because she knows my older son loves them.
When I put all these several occasions together, it’s clear we’ve been eating these cookies for at least 25 years. Because they freeze so well, my mom often bakes them off in quadruple batches and sends her Christmas Eve guests home with their own stash to store.
I’ve always loved how savory they are, and in my version of her recipe, I added grapefruit zest, increased the salt in the dough, and topped them with a salt-and-sugar mixture that adds a little crunch. Shortbread is about the least fussy dough a person could have to tackle—for this one you don’t even have to roll out and cut, you just smoosh everything into a baking pan and bake. I still managed to get crumbs on the floor when I took them out of the pan for serving, but that’s maybe just a “me” thing. —lallimusic
Line a 8 x 8-inch (20 x 20cm) baking pan (preferably glass) with parchment paper, leaving overhang on two sides. Whisk together all-purpose flour, rice flour, rosemary, and salt; set aside.
Combine the butter, 1/2 cup (100g) sugar, and grapefruit zest in the bowl of a stand mixer and beat with paddle attachment on medium-high speed until light and fluffy, 2 to 3 minutes, scraping down bowl as needed.
Add reserved flour mixture. Beat on low speed until crumbly, then increase speed to medium and beat until well combined, scraping down bowl as needed, about 2 minutes more. Transfer dough to prepared pan, then use an offset spatula to spread and press dough evenly into pan, smoothing top. Chill until firm, 1 hour.
Preheat oven to 375°F (190°C). Prick shortbread all over with a fork. Sprinkle evenly with remaining 1 tablespoon sugar, then sprinkle flaky salt over. Bake until golden brown around edges and evenly golden on surface, 30 to 35 minutes.
Remove from oven and immediately cut shortbread (still in pan) into four 2”-wide strips lengthwise. Rotate pan 90° and make eight 1-inch (2.5cm)-wide cuts perpendicular to the first ones to make 32 rectangular cookies. Let sit 10 minutes, then run a thin spatula around edges so that cookies don’t adhere to pan as they cool. Let cool completely in pan.
Using parchment, lift cookies out of pan and retrace cut marks if necessary to separate cookies.
A note on making these ahead: Cookies can be baked, cut, and cooled 1 week in advance. Transfer (on parchment) to an airtight container and store at room temperature, or freeze for up to 3 months.