Preheat oven to 195 F/90 C. Draw circles 2.5 inch/6 cm on parchment paper. Turn the paper over so that the drawing is facing down.

To make the meringue, open a capsule of Ristretto and place ground coffee aside. Using an electric or stand mixer, beat egg whites (at room temperature), gradually add granulated sugar and whick till the meringue becomes glossy. Once egg whites are set, add powdered (icing) sugar, ground coffee and mix with a rubber spatula. Place the meringue in a pastry bag with Ateco plain pastry tip 806 and pipe small spirals/rosettes onto drawn circles. Bake meringues for 2 hours. Turn off the oven and leave the meringues with the door closed for another one hour. 

To make the whipped cream, whisk cold whipping cream, gradually adding granulated sugar. Use an electric mixer to whip the cream until stiff.

To assemble sandwich meringues, pipe the whipped cream on the meringue rosette. Finish with another meringue on top, placing upside down (flat side up). Garnish edges and cover the top of sandwiched meringues with the cream. Smooth their sides and top, using a bent spatula. Place the meringues on a board and cover top of each meringue with the cream. Place meringues in the freezer for about 10 minutes before rolling them in chocolate chips.

To make chocolate chips, scrape a chocolate bar with a large knife, a vegetable peeler or use a mandoline slicer. Place chocolate chips in a large dish. Roll each sandwiched meringue in chocolate chips, except the bottom. Refrigerate.