This is one of our trickier recipes. But your patience will be rewarded with some delicious cookies that have a satisfyingly chewy texture.
You will need a food processor fitted with the blade attachment, and a pastry bag (or quart size resealable zip lock bag with the corner cut off) fitted with a 3/8 inch plain tip, and an offset spatula.
Makes about 2 dozen cookie sandwiches.
for the macarons:
3 oz almond flour (2/3 cup) or blanched sliced almonds (3/4 cup) or slivered almonds (2/3 cup)
1 1/2 cups confectioners sugar
1 tablespoon instant-espresso powder
1 teaspoon pure vanilla extract
3 large egg whites, at room temperature 30 minutes
1/4 teaspoon salt
3 tablespoons granulated sugar
for the filling:
3 1/2 cups raspberry jam
preparation
1. Line 2 large baking sheets with parchment paper.
2. Grind almond flour or almonds with confectioners sugar in food processor until powdery, 30 seconds for almond flour, about 2 minutes for almonds. (If using grinder, grind in small batches.) Sift through a medium-mesh sieve into a bowl (if not fine enough for almost all of nuts to go through sieve, regrind). Sift again into a large bowl.
3. Stir together espresso powder and vanilla in a cup until powder has dissolved.
4. Beat egg whites with salt in a bowl with an electric mixer at medium speed until they just hold soft peaks. Beat in granulated sugar, a little at a time. Increase speed to high and beat until meringue holds stiff, glossy peaks, about 1 minute. Add espresso mixture and mix at low speed until incorporated. Fold meringue into almond mixture with a rubber spatula until completely incorporated. (Meringue will deflate and batter will be loose.)
5. Put small dabs of batter under corners of parchment to secure to baking sheets.
6. Spoon half of batter into pastry bag. Holding bag vertically just above baking sheet, pipe 1 1/2-inch-wide mounds of batter about 1 inch apart, stopping pressure and flicking tip sideways to avoid peaks (tamp down any peaks with a wet finger). Refill pastry bag and repeat. Let macarons stand, uncovered, at room temperature until a light crust forms, 20 to 30 minutes.
7. Meanwhile, preheat oven to 300°F with racks in upper and lower thirds.
8. Bake macarons, switching position of sheets halfway through, until crisp and interior does not give easily when a macaron is gently pressed, 22 to 28 minutes total. Cool completely on baking sheets (for residual heat to harden bottoms) then on racks, about 30 minutes. Loosen macarons from parchment with offset spatula (they will be fragile).
9. Sandwich flat sides of macarons together with a thin layer of jelly.
10. Layer macarons between sheets of parchment in an airtight container and let stand at room temperature at least 2 hours to soften before eating.
Filled macarons can be kept in an airtight container wrapped in plastic wrap, chilled 2 days or frozen 1 month. Bring to room temperature in wrapped container (to avoid condensation), about 1 hour if chilled or 2 hours if frozen.