Cat's Tongues / Lingue di Gato

Directions

1. Preheat the oven to 450º and position the racks in the center and upper part of the oven. Line two cookie sheets with parchment paper, or lightly butter and flour them. In a bowl, with an electric mixer, beat the butter, sugar, and vanilla until creamy. Gradually beat in the flour, a few spoonfuls at a time.
2. In a clean bowl, with clean beaters, beat the egg whites until stiff but not dry peaks form. Fold the whites into the butter mixture, taking care not to deflate the whites.
3. Fill a pastry bag fitted with a 1/2-inch plain tip with the batter and pipe out 3-inch-long cookies on the cookie sheets, spacing them 1 inch apart.
4. Bake for 5 to 7 minutes, rotating the sheets once, until the cookies are firm to the touch but still pale and only very lightly browned around the edges. Remove them to cooling racks.
5. If making the glaze, bring 2 cups of water to a simmer in the base of a double boiler. Turn off the heat. Place the chocolate in the top of the double boiler and let sit, stirring occasionally, until it melts.
6. Spread the tops of the cookies with a thin layer of glaze, and let it set. Or use the glaze to sandwich the cookies.