Lemon-Blueberry Loaf

Preparation

1. Step 1

   Place a rack in middle of oven; preheat to 350°. Lightly coat a 9x5" loaf pan with nonstick vegetable oil spray. Line with parchment paper, leaving overhang on long sides. Whisk together ⅔ cup sour cream, room temperature, 2 Tbsp. vegetable oil, and 1 Tbsp. vanilla extract in a medium bowl until smooth.

   Step 2

   Beat 1⅔ cups (208 g) all-purpose flour, 1 cup plus 2 Tbsp. (225 g) granulated sugar, ½ cup (1 stick) unsalted butter, room temperature, 2 Tbsp. finely grated lemon zest, 1½ tsp. Diamond Crystal or 1 tsp. Morton kosher salt, 1 tsp. baking powder, and ¼ tsp. baking soda in the bowl of a stand mixer fitted with the paddle attachment, starting on low speed and gradually increasing to medium-low as flour is incorporated, until butter is combined and fine crumbs form, about 3 minutes. Increase speed to medium and, with motor running, gradually add sour cream mixture. Beat, scraping down the sides of bowl as needed, until no pockets of dry flour remain, about 2 minutes. (Batter will be very thick.) Add 1 large egg, room temperature, and beat just until combined. Add remaining 1 large egg, room temperature; beat until combined and remove bowl from mixer.

   Step 3

   Toss together 1¼ cups frozen blueberries and remaining 1 Tbsp. (8 g) all-purpose flour in a small bowl to coat. Scrape about one third of the batter into prepared pan and spread into an even layer. Scatter about one third of blueberries over, shaking to remove any excess flour. Scrape half of remaining batter on top and spread into an even layer. Scatter half of remaining blueberries over. Repeat layers one more time with remaining batter and blueberries. (Do not press blueberries into batter. They will naturally sink.) Discard any flour left in bowl.

   Step 4

   Bake cake until top is golden brown and a tester inserted into the center comes out with just a few moist crumbs attached, 70–80 minutes. (Do not start checking the cake early or attempt to rotate it as opening the oven will risk causing the cake to sink. Open only after the 70-minute mark.) Transfer pan to a wire rack and let cake cool in pan until just barely warm. Turn cake out onto rack and let cool completely. (The top of the cake will flatten slightly as it cools.)

   Step 5

   Whisk 1 cup (110 g) powdered sugar, 1 Tbsp. plus 1 tsp. fresh lemon juice, and a pinch of kosher salt in a small bowl until smooth. Glaze should be thick yet pourable. If too thin, whisk in more powdered sugar. If too thick, whisk in more lemon juice. Pour glaze over cake, allowing glaze to drip down sides slightly. Let sit at least 1 hour to allow glaze to set before slicing.