1
Preheat the oven to 325 degrees F.
2
Sift the flour and toss it with the almond and sugar powder.
3
Whip the egg whites in an electric mixer at low speed until they start to froth. If you are not whipping the whites in a copper bowl, then add the cream of tartar at this point.
4
Gradually increase the whipping speed to medium-high, and continue whipping until the whites form very stiff peaks and just begin to slip and streak around the side of the bowl.
5
Add the superfine sugar and continue whipping at high speed for a few seconds longer to incorporate the sugar and tighten the meringue.
6
Gently fold in the almond and sugar powder and flour.
7
Scoop the batter into the pastry bag, and pipe the batter in domes 1-inch wide, arranging them on the baking sheets in staggered rows and separating them by about 1-inch. Unless you have 2 ovens, pipe only 1 sheet of cookies at a time, and keep the remaining batter in the pastry bag until the first sheet is baked.
8
Dust chopped almonds over the piped batter. Turn the baking sheet upside down and tap it with a wooden spatula to dislodge the excess almonds, then quickly turn the baking sheet right side up again.
9
Dust with confectioners' sugar.
10
Let rest for about 1 minute to allow some of the confectioners' sugar to dissolve. Bake, 1 sheet at a time, until the cookies are lightly browned on the bottom and dry and crusty on top, but still soft inside, about 15 to 18 minutes.
11
Place the baking sheet on a wire rack and let the cookies cool. While they are still warm and before the batter sets, carefully transfer them to a wire rack with a metal spatula. Then let them finish cooling on the wire rack.
12
Press the center of each dome on the flat side with your fingertip to make a slight depression.
13
Turn half the domes upside down and spoon about 1/2 teaspoon of apricot jam on the center of each. Then place a second dome right side up on top of each to make a sandwich.
14
Lightly dust the balls with confectioners' sugar, then turn them upside down and dust the other side as well.
15
Storage: Covered airtight in a tin cookie box or a cookie jar for up to 4 to 6 days. They look best if they are dusted with confectioners' sugar shortly before serving.