I've started keeping black cocoa on hand (as well as natural cocoa and regular Dutched cocoa), but I don't come across recipes that call for it that often. When I saw Edd Kimber's recipe for Black Cocoa Peanut Sandwich Cookies, I loved the look of the cookies -- black as night, studded with peanuts, and sandwiched around a creamy filling the dark golden color of butterscotch. And the cookies are easy to make, so I didn't hesitate to give the recipe a try.
For the cookies, you beat softened butter until creamy; add vanilla; and incorporate the dry ingredients (flour, black cocoa, powdered sugar, and cornstarch). You scoop out the dough, roll each cookie in chopped salted peanuts, and flatten the cookies before baking. I used a #50 scoop and got the exact specified yield -- 30 cookies, enough to make 15 sandwiches. I found that for the best results, I needed to flatten the cookies as much as possible, but I was constrained by the thickness of the peanuts (which I hadn't chopped with a knife, but put into a plastic bag and bashed with a rolling pin). In the future, I would pulse the peanuts in a food processor to get smaller pieces.
I thought the finished cookies looked great. Even though the cookies weren't entirely uniform and the filling didn't have a completely smooth finish like those in the photo accompanying the recipe, they were still so eye-catching and dramatic. But they were disappointing. First, the texture of the cookie was extremely sandy, basically dissolving into fine crumbs at the first bite. I have no objection to sandy cookies in general, but I did not like it here. Second, there was almost no chocolate flavor in the cookies at all. While the black cocoa certainly did its job when it comes to giving the cookies color, black cocoa doesn't have the strong chocolate flavor of regular Dutch cocoa powder. And the weak chocolate flavor was all the more disappointing in light of the deep black color telegraphing a signal to my brain to expect a ton of flavor.
The peanut butter-white ganache filling in the cookies was fantastic, though -- I might try it as a filling in a different sandwich cookie. The first one that comes to mind is the Farmeeoh, an Oreo knockoff from The Farm of Beverly Hills. I think coating the Farmeeoh cookies in peanuts before baking would also probably work. Some all peanut-butter sandwich cookie options would be Abby Dodge's Chunky Oatmeal Peanut Butter Sandwiches, Karen DeMasco's Peanut Butter Sandwich Cookies with Milk Chocolate Filling, or Rosie Daykin's Peanut Butter Sandwich Cookies.
These cookies weren't bad by any means, but I thought they were a little more flash than substance.
Recipe: "Black Cocoa Peanut Sandwich Cookies" by Edd Kimber.