Pistachio Rhubarb Yogurt Cake

Ingredients

• 1 stick (½ cup) plus 1 tablespoon unsalted butter, room temperature, plus more for pan
• 2 cups plain whole-milk yogurt
• 1 pound rhubarb, trimmed and cut crosswise into 3-inch pieces
• 1 ½ cups sugar, plus more for sprinkling
• 1 ¾ teaspoons kosher salt
• ½ cup shelled unsalted pistachios (2 ¼ ounces)
• 1 ½ cups unbleached all-purpose flour
• 2 teaspoons baking powder
• 2 large eggs, room temperature
• 1 ¼ teaspoons pure vanilla extract or orange-blossom water
• ¼ cup confectioners' sugar

Instructions

1. 1
   Preheat oven to 400 degrees. Butter an 8-inch-round, 2-inch-deep cake pan and line bottom with parchment; butter parchment. Place 1 cup yogurt in a fine-mesh sieve set over a bowl; let drain in refrigerator.
2. 2
   Meanwhile, toss together rhubarb, 1/2 cup granulated sugar, 1 tablespoon butter, and 1/4 teaspoon salt on a rimmed baking sheet. Roast, stirring once, just until tender, about 15 minutes. Reduce oven temperature to 325 degrees.
3. 3
   In a food processor, finely grind pistachios. Add flour, baking powder, and remaining 1 1/2 teaspoons salt; pulse to combine. Beat together remaining 1 stick butter and 1 cup granulated sugar with a mixer on medium-high speed until light and fluffy. Beat in eggs, one at a time, then vanilla. Reduce speed to low and beat in flour mixture in two batches, alternating with remaining 1 cup yogurt.
4. 4
   Transfer batter to pan and smooth top. Arrange about half of rhubarb over top; refrigerate remaining rhubarb in syrup until ready to serve. Sprinkle cake with granulated sugar and bake until a tester inserted in center comes out clean, about 1 hour, 15 minutes (if browning too quickly, tent with foil). Transfer pan to a wire rack and let cool 15 minutes. Run a small sharp knife around edges. Invert onto a cutting board, then immediately flip onto rack; let cool completely.
5. 5
   Stir confectioners' sugar into drained yogurt. Chop remaining rhubarb and swirl into yogurt, along with some syrup. Serve cake with yogurt, drizzled with more syrup.