- 1 cup sugar
- 1/2 cup light corn syrup
- 1/3 cup water
- 1/2 cup (1 stick) unsalted butter, cut into 1-inch pieces
- 1/8 teaspoon salt
- 3/4 cup heavy whipping cream
- 1/3 cup strong brewed decaffeinated coffee
- 1 1/3 cups whole milk
- 1 cup heavy whipping cream
- 1/2 vanilla bean, split lengthwise
- 3/4 cup (packed) golden brown sugar
- 5 large egg yolks
- Pinch of salt
- 1 tablespoon Jack Daniel's or bourbon
- 1 cup plus 2 tablespoons all purpose flour
- 1/2 cup powdered sugar
- 1/4 cup unsweetened cocoa powder
- 1/4 teaspoon salt
- 10 tablespoons (1 1/4 sticks) chilled unsalted butter, cut into 1/2-inch cubes
- 3 tablespoons (or more) ice water
- 1 1/3 cups toasted hazelnuts (about 7 ounces), husked, cooled
- 9 ounces bittersweet chocolate, chopped
- 1/4 teaspoon salt
- 1 cup heavy whipping cream
- 1/2 cup whole milk
- 1/4 cup sugar
- 1 large egg
- 1 large egg yolk
- Stir sugar, corn syrup, and 1/3 cup water in heavy large saucepan over medium-low heat until sugar dissolves. Increase heat to high and boil without stirring until mixture turns deep amber, occasionally swirling pan and brushing down sides with wet pastry brush, about 7 minutes. Remove from heat and immediately add butter and salt (mixture will bubble vigorously). Stir until butter melts. Add cream and coffee; whisk to blend. Cool. DO AHEAD: Can be made 3 days ahead. Cover and chill.
- Stir sugar, corn syrup, and 1/3 cup water in heavy large saucepan over medium-low heat until sugar dissolves. Increase heat to high and boil without stirring until mixture turns deep amber, occasionally swirling pan and brushing down sides with wet pastry brush, about 7 minutes. Remove from heat and immediately add butter and salt (mixture will bubble vigorously). Stir until butter melts. Add cream and coffee; whisk to blend. Cool. DO AHEAD: Can be made 3 days ahead. Cover and chill.
- Whisk sugar, egg yolks, and pinch of salt in medium bowl. Gradually whisk milk mixture into egg mixture; return to saucepan. Stir over medium heat until thickened slightly and finger leaves path when drawn across spoon, about 4 minutes (do not boil). Strain into another medium bowl. Stir in Jack Daniel's. Cover and chill custard until cold, at least 5 hours.
- Process custard in ice cream maker according to manufacturer's instructions. Transfer ice cream to container, cover, and freeze. DO AHEAD: Can be made 1 day ahead. Keep frozen.
- Blend flour, sugar, cocoa powder, and salt in processor. Add butter. Using on/off turns, process until coarse meal forms. Add 3 tablespoons ice water; using on/off turns, process until moist clumps form, adding more water by teaspoonfuls if too dry. Form dough into ball; flatten into disk. Wrap in plastic and chill dough 1 hour. DO AHEAD: Can be made 1 day ahead. Keep chilled.
- Preheat oven to 350°F. Divide dough into 6 equal portions. Press 1 dough portion onto bottom and up sides of each of six 4 1/2×1/2- inch tartlet pans with removable bottoms. Freeze crusts 30 minutes.
- Bake crusts until dry and set, about 15 minutes. Cool completely.
- Preheat oven to 350°F. Grind nuts in processor until paste forms. Transfer to bowl. Add chocolate and salt to bowl. Bring cream and milk just to boil in small saucepan; pour over chocolate mixture in bowl. Whisk until chocolate melts. Cool to room temperature, stirring occasionally. Add sugar, egg, and egg yolk; whisk until smooth.
- Pour filling into cooled tartlet crusts, dividing equally. Bake until filling is set and some small cracks appear on surface, about 15 minutes. Cool. DO AHEAD: Can be made 6 hours ahead. Let stand at room temperature.
- Remove pan sides from tartlets. Place 1 tartlet on each of 6 plates. Serve with scoop of ice cream and drizzle with sauce.