Preheat oven to 225°F. Line 2 heavy large baking sheets with foil; butter and flour foil. Combine 1 cup pecans, 3 tablespoons sugar, cinnamon and salt in processor; grind finely. Add 1 1/2 ounces (about 1/4 cup) chocolate and 1 cup nuts and process just until pecans are coarsely chopped, using about 10 on/off turns.

Using electric mixer, beat egg whites and 1/4 teaspoon cream of tartar in medium bowl until soft peaks form. Gradually add 1/2 cup brown sugar, beating until mixture is very stiff, about 4 minutes. Fold in nut mixture and instant coffee (crystals will not dissolve).

Drop batter by scant tablespoonfuls onto prepared sheets, spacing evenly. Lightly press pecan half onto each cookie. Bake until meringues are dry, about 55 minutes. Cool completely on sheets.

Place 1 tablespoon ice cream on bottom side of 1 meringue. Gently press bottom side of another meringue onto ice cream. Place on baking sheet; freeze. Repeat with remaining meringues and ice cream. Freeze until firm, about 1 hour.

Melt 3 ounces chocolate in top on double boiler set over simmering water, stirring until smooth. Drizzle over sandwiches. Cover and freeze. (Can be made 2 days ahead. Keep frozen.)

Serves 8 to 10.