Of all the types of recipes out there, baking recipes can be the most cryptic.
After all, how often do you see phrases like, "Have ready 1/4 cup mirepoix in brunoise" in your standard...
Capturing the flavor of fresh basil in baked goods is not easy or obvious. Certain herbs have strong, lasting aromas that lend themselves to cooking--rosemary and thyme are good examples. But others have fugitive flavor compounds that are all but lost during the cooking process--namely, basil.
If you've done much cooking with basil, you know it can be a prima donna. It starts to turn black almost as soon as you cut it unless your knife is very, very sharp. You should never add basil to a dish until the last second because it will all but disappear under the other, more assertive, flavors. And, as any lover of pesto would attest, basil hates being exposed to air and turns a very unappealing shade of brownish black unless you cover it with oil. Dried basil exists, but it can never approximate the flavors of fresh basil, as much as we might want it to.
All these things limit the ways in which we use basil in the kitchen. Mostly, it's the sort of herb you want to throw onto a tomato salad. And it excels at that. But if you crave the flavor of basil in other applications, perhaps you've puzzled over the very issue I puzzled over yesterday: how can I make a basil shortbread that retains the flavor and color of fresh basil?
There are plenty of basil shortbread recipes out there that simply have you chop or chiffonade fresh basil and throw it in. This is fine, but in addition to the browning issue, you'll run into the problem of dispersal--getting the basil flavor into the whole cookie and not just little pockets where the basil bits are.
Perhaps I'm overcomplicating the issue (of course I am--I'm a baker), but all I wanted was a subtle, basil-perfumed tender shortbread cookie. Is that so much to ask?
The solution is fairly simple. To retain basil's beautiful green color, I blanched the herbs very, very briefly--as in, about 2 seconds. Rather than plunging the blanched herbs in ice water, though, I shook them out and put them in the freezer for just a few minutes--not long enough to freeze them, but long enough to cool them completely. This prevents the basil from getting waterlogged from sitting in ice water.
Then, I ground the basil in my spice grinder with cornstarch and milk powder. One of my secrets to a good shortbread is cornstarch--replacing a small portion of the flour with cornstarch makes for an exceptionally tender shortbread cookie. Milk powder also promotes tenderness and browning (I used buttermilk powder, so it also added a little hint of lovely, tart buttermilk flavor).
The resulting cookie is delicate, tender, fragrant, and very lightly green-tinged. It's a sophisticated take on basil shortbread that will have you reaching into the cookie jar time after time.
Bring a pot of water to a boil. Very quickly, plunge into the boiling water and immediately remove:
2 stems fresh basil (about 8 to 10 large basil leaves total)
Shake off as much excess water as possible from the leaves, spread them out on a baking sheet, and place them in the freezer just until they cool completely, no longer than 5 minutes.
Place the basil in a spice grinder with:
1/4 cup cornstarch
1/4 cup milk or buttermilk powder* or an additional 1/4 cup cornstarch
Grind until the basil is completely pulverized and has tinted the cornstarch mixture a light green color.
Cream together until very smooth:
1 cup (2 sticks) butter
1 cup confectioner's sugar
Zest of 2 lemons or limes
1/2 teaspoon salt
Add the cornstarch-basil mixture along with:
1 1/2 cups all-purpose flour
Stir in until just combined.
For icebox-style cookies, divide the dough in half and form each half into a log about 1 1/2 inches in diameter. Wrap the logs in parchment or plastic wrap and refrigerate for about an hour.
For rolled shortbtread cookies, divide the dough in half and flatten each half into a disk. Wrap in plastic and refrigerate for 30 minutes or so.
Preheat the oven to 325˚F. If using the icebox method, cut the rolls of dough into 1/4-inch thick cookies. Arrange the cookies on baking sheets about 1 inch apart and bake until just done but not browned, about 10 to 13 minutes (the cookies should feel dry on top, not tacky).
If using the rolling method, place one of the dough halves between two sheets of parchment. Using a rolling pin, roll the dough to 1/4-inch thickness. It may help to peel the parchment off the top, replace it, flip the dough, and remove the parchment from the bottom from time to time. This prevents the dough from sticking to the parchment and getting bunched up or cracking. Cut the cookies using a cookie cutter of your choosing. Bake as above.
*You can find buttermilk powder at online retailers such as Bob's Red Mill. Buttermilk powder is also perfect for any recipe that calls for buttermilk--simply mix up as much as you need for the recipe and never have to throw a mostly unused carton of buttermilk away again.