4 tablespoons (1/2 stick) unsalted butter, melted, plus more for greasing the baking dish
1 cup fresh orange juice plus 2 tablespoons finely grated orange zest
1/4 cup water
1/2 cup heavy cream
1 tablespoon fresh lemon juice
Scraped seeds from 1 1/2 vanilla beans, or 1 1/2 tablespoons vanilla bean paste
About 1 cup (120 grams) unbleached all-purpose flour
1/2 cup sugar
2 teaspoons baking powder
1/4 teaspoon salt
Vanilla ice cream, for serving
Preheat the oven to 350 degrees. Lightly grease an 8-inch-square baking dish with a little melted butter.
Combine the orange juice and water in a saucepan; bring it to a boil over medium-high heat.
Meanwhile, whisk together the orange zest, cream, melted butter, lemon juice and vanilla bean seeds or paste in a small bowl.
Whisk together the flour, sugar, baking powder and salt in a medium bowl. Add the orange zest mixture and stir just until incorporated to form a stiff batter. Transfer it to the prepared baking dish, smoothing the top with a spatula. Set the baking dish on the middle oven rack, then carefully pour the boiling liquid over the surface of the batter. Bake for 27 to 35 minutes, until the cake has a crisp, golden surface and the pudding sauce on the bottom is bubbling.
Spoon the warm pudding cake into each plate. Top each portion with a small scoop of ice cream. Serve right away