- 1/4 vanilla bean, halved lengthwise
- 2 cups heavy cream
- 4 large egg yolks
- 1/4 cup sugar
- 1/2 vanilla bean, halved lengthwise
- 2 cups fresh orange juice
- 1 cup sugar
- 2 tablespoons Grand Marnier or other orange liqueur
- 1/2 cup unsalted shelled natural pistachios
- 1/4 cup granulated sugar
- 1 cup all-purpose flour
- 1/4 teaspoon salt
- 1 cup whole milk at room temperature
- 2 tablespoons unsalted butter, melted
- 3 large eggs at room temperature
- 2 tablespoons superfine granulated sugar
- Special equipment: a 9- by 5- by 3-inch glass loaf pan; a nonstick popover pan with 6 (51/2-oz) cups; a blowtorch
- Scrape seeds from vanilla bean into cream in a 2-quart heavy saucepan, then add pod and bring to a simmer over moderate heat. Remove from heat, then steep, covered, 20 minutes.
- Discard pod.
- Preheat oven to 325°F.
- Whisk together yolks, sugar, and a pinch of salt, then add hot cream in a slow stream, whisking constantly. Pour through a fine sieve into glass loaf pan. Cover pan with foil and bake custard in a hot water bath until set but with center still slightly wobbly, about 1 hour.
- Remove foil and cool custard in pan on a rack, then chill, covered, until firm, at least 4 hours.
- Scrape seeds from vanilla bean into juice in cleaned 2-quart heavy saucepan, then add pod and sugar. Bring to a boil over moderately high heat, stirring until sugar is dissolved, then boil until reduced to about 1 1/4 cups, about 20 minutes. Remove from heat, then discard pod and stir in Grand Marnier. Cool to room temperature.
- Preheat oven to 375°F.
- Chop enough pistachios to measure 2 tablespoons. Pulse remaining nuts with regular granulated sugar in a food processor until finely ground. Add flour and salt and pulse to combine. Add milk, butter, and eggs and blend until just combined. Pour batter into well-buttered popover cups, filling them two-thirds full.
- Bake in lower third of oven until popovers are puffed and well browned, about 40 minutes. Cut a 1/2-inch slit in top of each popover and bake 10 minutes more. Immediately turn popovers out onto rack to cool.
- Cut off tops of cooled popovers and arrange in a baking dish. Brush tops with some syrup and heat in oven until warm, about 3 minutes.
- While tops are heating, fill bottoms of popovers with custard. Sprinkle 1 teaspoon superfine sugar evenly over each custard, then move blowtorch flame evenly back and forth just over sugar until sugar is melted and caramelized.
- Transfer popovers with tops to plates and spoon some syrup around each. Sprinkle with chopped nuts.