Roasted Rhubarb Cobbler

INGREDIENTS

FOR THE RHUBARB FILLING:

• 1 vanilla bean, split lengthwise (or use 1/2 teaspoon vanilla paste or 1 tablespoon vanilla extract)
• 2 pounds rhubarb, trimmed and cut into 1/2-inch pieces (about 7 cups)
• ¾ cup/150 grams granulated sugar
• 1 teaspoon finely grated orange zest
•  Pinch of kosher salt

FOR THE BISCUIT TOPPING:

• ¾ cups/96 grams all-purpose flour, plus more for shaping
• 2 tablespoons granulated sugar
• 2 ¼ teaspoons baking powder
•  Pinch of kosher salt
• 3 tablespoon cold unsalted butter, cut into 1/2-inch cubes
• ⅓ cup/79 milliliters plus 1 tablespoon heavy cream, plus more for serving, if you like
•  Demerara sugar, for sprinkling
•  Ice cream, for serving (optional)

PREPARATION

1. Heat oven to 425 degrees. Using the tip of a paring knife, scrape the pulp out of the vanilla bean halves and add the pulp to a 1 1/2 quart gratin or baking dish or 9-by-9-inch pan along with the scraped-out pods. (Alternatively, add the paste or extract to the pan.) Add the rhubarb, sugar, zest and salt, and toss well. Let sit at room temperature to macerate while preparing the biscuit dough.
2. Make the biscuit dough: Put the flour, sugar, baking powder and salt in a food processor. Pulse to combine. Add cubed butter, then pulse until the mixture has formed lime bean-size pieces. Drizzle in 1/3 cup heavy cream and pulse until everything just clumps together, taking care not to overprocess. (To make the dough by hand, put the flour, sugar, baking powder and salt in a large bowl and whisk to combine. Add cubed butter, then mix it in with your hands, pinching and squeezing with your fingers — or use a pastry blender — until the largest pieces are the size of peas. Drizzle in 1/3 cup heavy cream a little at a time, mixing until the dough comes together.)
3. Dump the dough onto a lightly floured surface, and gently pat it together until it’s a cohesive lump. Using a small ice cream scoop or a large spoon, form dough into 6 evenly sized balls. Slightly flatten dough balls into thick rounds. Cover rounds with plastic wrap and chill for at least 30 minutes (and up to 6 hours).
4. Put the rhubarb in the oven and roast, stirring halfway through, until the rhubarb has softened and the liquid has formed a syrup, about 30 minutes.
5. Remove pan from oven and use tongs to remove the vanilla bean pods.
6. Lower oven temperature to 375 degrees. Arrange biscuit rounds on top of the rhubarb, leaving space in between them. Brush biscuits with remaining tablespoon of heavy cream and sprinkle with Demerara sugar.
7. Bake cobbler until biscuits are golden brown, about 25 to 35 minutes. Serve warm or at room temperature, with cream or ice cream, if you like.