For the Meringue Cookies- 6 egg whites- 1/2 teaspoon cream of tartar- 2/3 cup sugar- 1 cup roasted unsalted cashews- 1/4 cup flour- 1 teaspoon vanilla extractFor the French Buttercream- 1/2 cup sugar- 3 tablespoons water- 5 egg yolks- 8 ounces (2 sticks) butter, softened and at room temperatureFor Assembling Silvanas- 2 cups roasted unsalted cashews- 1 cup graham cracker crumbs
For the Meringue Cookies- In a food processor, blend together all-purpose flour and 1 cup cashews until fine. Set aside.- Preheat oven to 325 F. - Line a cookie sheet with parchment paper. Using a marker, trace several circles about 2.5 inches diameter on the parchment with about 1 1/2 inches of space in between.- In the bowl of a stand mixer, beat the egg whites on medium-high speed until foamy. - Sprinkle in cream of tartar and continue to beat until soft peaks form.- Gradually add sugar and continue to beat until stiff peaks form. - Using a rubber spatula, gently fold in the vanilla and the ground cashews/flour mixture in three additions.- Transfer the meringue into a large piping bag fitted with a large piping tip. Following the circles as a guide, pipe circles that are about 1/2 inch high on the parchment paper. - Using a small knife or an offset spatula, smoothen and flatten tops of the meringue. Gently tap the baking sheet on the counter to remove any bubbles.- Bake the meringue in a 325 F oven for about 18 to 20 minutes, or until lightly golden. The edges will be tender-crisp and the middles are soft. - Using a spatula, carefully transfer cookies to a cooling rack and let cool completely.For the French Buttercream- In a medium saucepan, combine sugar and water and stir. Cook the mixture over medium heat. Once boiling, place a candy thermometer in the pan to monitor the temperature.- Meanwhile, start to beat the egg yolks on a stand mixer on high speed until thickened and pale in color. - Continue to beat yolks until the water and sugar mixture on the stove registers 238 F. Turn the heat off and slowly pour the sugar syrup in a thin, continuous stream into the yolks with the mixer running.- Continue to beat the yolk mixture until the mixing bowl is cool to the touch. - With the mixer still running, add the softened butter, about a tablespoon at a time, and beat until a fluffy buttercream forms.Assembling the Silvanas- In a food processor, process the 2 cups of cashews until resembles fine crumbs.- Spread a thin layer of buttercream on the rough side of a cookie ( the side that was facing up during baking). Top it with another meringue cookie with the rough side against the buttercream. - Spread more buttercream on the sides and the base of cookies to completely cover. - Roll the buttercream-covered cookie sandwiches in ground cashews. Roll the other cookies in graham cracker crumbs.- On a parchment-lined baking sheet, arrange silvanas in a single and freeze for about 1 to 2 hours or until firm.- For longer storage, transfer the cookies into an airtight container and keep frozen until ready to serve.