Cashew Flour Macarons with chocolate ganache

1  cup		powdered sugar
5  ounces		cashew flour
1-1/2  ounces		egg whites
1/8  teaspoon		cream of tartar
1/4  cup		superfine sugar
17  tablespoons		Chocolate Ganache [recipe]

Tip: For nutritional information on all the ingredients in Cashew Flour Macarons with chocolate ganache just click on each ingredient name. Then adjust the serving size for any Cashew Flour Macarons with chocolate ganache ingredient with the serving size tool in the nutrition facts area to the right to see how you can save calories, carbs and more.

Pulse confectioners' sugar and cashew flour in a food processor until combined. Sift mixture 2 times.
WATCH: How to Sift Flour Without a Sieve
Preheat oven to 375 degrees. Whisk whites with a mixer on medium speed until foamy. Add cream of tartar, and whisk until soft peaks form. Reduce speed to low, then add superfine sugar. Increase speed to high, and whisk until stiff peaks form, about 8 minutes. Sift flour mixture over whites, and fold until mixture is smooth and shiny.
WATCH: How to Fold
Transfer batter to a pastry bag fitted with a 1/2-inch plain round tip, and pipe 3/4-inch rounds 1 inch apart on parchment-lined baking sheets, dragging pastry tip to the side of rounds rather than forming peaks. Tap bottom of each sheet on work surface to release trapped air. Let stand at room temperature for 15 minutes. Reduce oven temperature to 325 degrees. Bake 1 sheet at a time, rotating halfway through, until macarons are crisp and firm, about 10 minutes. After each batch, increase oven temperature to 375 degrees, heat for 5 minutes, then reduce to 325 degrees.
Let macarons cool on sheets for 2 to 3 minutes, then transfer to a wire rack. (If macarons stick, spray water underneath parchment on hot sheet. The steam will help release macarons.)
Sandwich 2 same-size macarons with 1 teaspoon filling. Serve immediately.