Ground walnuts and hazelnuts take the place of flour in this gluten-free, deeply chocolate cookie. Cream of tartar helps stabilize whipped egg whites so they keep their volume when mixed with the nuts and melted chocolate. And each cookie contains approximately 8 g of diced prunes, the equivalent of one prune.
Yield: 13 cookies
50 g / 1/2 cup walnuts, lightly toasted
50 g / 1/2 cup hazelnuts, lightly toasted
2 g / 1/2 teaspoon salt
113 g / 4 ounces bittersweet chocolate
60 g / 2 egg whites, at room temperature
45 g / 1/4 cup sugar
.5 g / 1/8 teaspoon cream of tartar
105 g / 3/4 cup Diced Prunes
In a food processor, grind the walnuts, hazelnuts, and salt into a coarse meal. (Do not over-process.)
Melt the chocolate in a heat-proof bowl over a pot of barely simmering water or a microwave. Stir with a rubber spatula and let cool slightly.
Preheat the oven to 350F [180 C]. Line two 46-by-13-cm [18-by-13-in] half-sheet pans with parchment paper.
In a stand mixer fitted with a whisk attachment, whip the egg whites, sugar, and cream of tartar until the whites hold stiff peaks when the whisk is removed from the bowl, about 2 minutes. Gently fold in the chocolate and nuts, then fold in the dried plums.
Using a 30 ml [2 tablespoon] scoop, portion onto the prepared pans. Bake until firm on the outside but still soft in the center, about 12 minutes. Let cool on the sheet pans.