1 1/2 c. water
1/2 c. sugar
2 1/2 tbsp. instant espresso powder
12 oz. semi-sweet chocolate, chipped
6 tbsp. (3/4 stick) unsalted butter

CRUST:

3 c. macaroon cookie crumbs (about 21 Mother's brand cookies)
1/4 c. (1/2 stick) unsalted butter, melted

FILLING:

2 pts. chocolate ice cream
2 pts. coffee ice cream

or Heath bars (about 14 Almond Roca or 12 miniature Heath bars, about 5 oz.)

For sauce: Cook water, sugar and espresso in heavy medium saucepan over low heat, stirring until sugar dissolves. Add chocolate and butter. Stir until chocolate and butter are melted and sauce is smooth. Cool completely. (Sauce can be prepared 3 days ahead. Cover and refrigerate. Bring sauce to room temperature before using.)

For crust: Oil 9 inch springform pan. Mix 2 cups crumbs and butter in medium bowl. Press firmly into bottom of prepared pan. Freeze until firm.

For filling: Soften chocolate ice cream in refrigerator until spreadable but not melted. Spread in pan and smooth top. Repeat for coffee ice cream. Spoon 1/2 cup more sauce over coffee ice cream and top with Roca or Heath.

Spoon 1/2 cup sauce over ice cream and sprinkle with remaining 1 cup cookie crumbs. Freeze until firm.

Heat balance of sauce and serve over ice cream cake.