FRENCH MACARONS

Steps:

• Preheat the oven to 300 degrees F using the convection setting. Line 3 baking sheets with silicone mats. Measure the confectioners' sugar and almond flour by spooning them into measuring cups and leveling with a knife. Transfer to a bowl; whisk to combine.
• Sift the sugar-almond flour mixture, a little at a time, through a fine-mesh sieve into a large bowl, pressing with a rubber spatula to pass through as much as possible. It will take a while, and up to 2 tablespoons of coarse almond flour may be left; just toss it.
• Beat the egg whites, cream of tartar and salt with a mixer on medium speed until frothy. Increase the speed to medium high; gradually add the superfine sugar and beat until stiff and shiny, about 5 more minutes.
• Transfer the beaten egg whites to the bowl with the almond flour mixture. Draw a rubber spatula halfway through the mixture and fold until incorporated, giving the bowl a quarter turn with each fold.
• Add the food coloring and extract (see below). Continue folding and turning, scraping down the bowl, until the batter is smooth and falls off the spatula in a thin flat ribbon, 2 to 3 minutes.
• Transfer the batter to a pastry bag fitted with a 1/4-inch round tip. Holding the bag vertically and close to the baking sheet, pipe 1 1/4-inch circles (24 per sheet). Firmly tap the baking sheets twice against the counter to release any air bubbles.
• Let the cookies sit at room temperature until the tops are no longer sticky to the touch, 15 minutes to 1 hour, depending on the humidity. Slip another baking sheet under the first batch (a double baking sheet protects the cookies from the heat).
• Bake the first batch until the cookies are shiny and rise 1/8 inch to form a "foot," about 20 minutes. Transfer to a rack to cool completely. Repeat, using a double sheet for each batch. Peel the cookies off the mats and sandwich with a thin layer of filling (see below).
• Almond-Raspberry:
• Tint the batter with 2 drops neon pink gel food coloring; flavor with almond extract. Fill with seedless raspberry jam (you'll need about 3/4 cup).
• Mint-White Chocolate:
• Tint the batter with 2 drops mint green gel food coloring; flavor with mint extract. For the filling, microwave 3 ounces chopped white chocolate, 2 tablespoons heavy cream and 1 tablespoon butter in 30-second intervals, stirring, until smooth. Stir in 1/4 teaspoon mint extract and 1 drop mint green gel food coloring.
• Blueberry Cheesecake:
• Tint the batter with 3 drops royal blue gel food coloring; flavor with vanilla extract. For the filling, mix 4 ounces softened cream cheese and 3 tablespoons blueberry jam.
• Lavender-Honey:
• Tint the batter with 2 drops violet gel food coloring; flavor with almond or vanilla extract. For the filling, mix 3/4 cup mascarpone cheese, 2 tablespoons honey and 1 teaspoon ground dried lavender.
• Pineapple:
• Tint the batter with 2 drops lemon yellow gel food coloring; flavor with vanilla extract. For the filling, press 3/4 cup pineapple jam through a sieve, discarding any large pieces.