- 1 cup plus 2 tablespoons sugar
- 1/2 cup (1 stick) unsalted butter
- 1/4 cup water
- 10 ounces bittersweet (not unsweetened) chocolate, chopped
- 3 large eggs
- 1 teaspoon vanilla extract
- 1 cup plus 2 tablespoons unbleached all purpose flour
- 1 1/2 teaspoons baking soda
- 1 teaspoon salt
- 3/4 cup chopped macadamia nuts
- 1 1/2 to 2 quarts vanilla ice cream, softened slightly
- 8 ounces bittersweet (not unsweetened) or semisweet chocolate, chopped
- 1/2 cup hot coffee or 1 1/2 teaspoons instant expresso powder dissolved in 1/2 cup hot water
- 6 tablespoons Frangelico (hazelnut liqueur)
- Preheat oven to 325 °F. Line 17 1/4×11 1/2×1-inch baking sheet with parchment. Bring sugar, butter and water to boil in heavy large saucepan over medium heat, stirring until sugar dissolves. Reduce heat to low. Add chocolate; stir until smooth. Whisk eggs and vanilla in large bowl to blend. Gradually whisk in hot chocolate mixture. Mix in flour, baking soda and salt, then nuts.
- Spread butter over prepared sheet. Bake until toothpick inserted into center comes out clean, about 20 minutes. Cool completely. Freeze until firm.
- Cut around brownie to loosen. Turn out onto work surface. Peel off parchment. Trim brownie to 16×10-inch rectangle; cut in half crosswise, making two 8×10-inch rectangles. Place 1 rectangle on baking sheet. Cover brownie with ice cream. Freeze until slightly firm.
- Lightly score top of remaining brownie in half lengthwise, then score across, in 2-inch sections, making 10 2×4-inch rectangles.
- Press scored brownie atop ice cream, scored side up. Freeze until ice cream is firm, at least 4 hours. Cut brownie along marked lines into 10 sandwiches. ( Can be made 2 weeks ahead. Wrap tightly; keep frozen.)
- Stir chocolate and coffee in saucepan over low heat until smooth. Add liquer. (Can be made 1 week ahead. Cover; chill. Rewarm before serving.)
- Serve sandwiches with sauce.