1¼ cups (284 grams) unsalted butter, softened1¾ cups (350 grams) granulated sugar2½ teaspoons (5 grams) lemon zest5 large eggs (250 grams), room temperature1 teaspoon (4 grams) vanilla extract2⅓ cups (292 grams) plus 2 tablespoons (16 grams) all-purpose flour, divided1½ teaspoons (4.5 grams) kosher salt½ teaspoon (2.5 grams) baking soda½ cup (120 grams) whole buttermilk, room temperature1⅔ cups (250 grams) fresh blueberriesGarnish: confectioners’ sugar
Preheat oven to 325°F (170°C).
In the bowl of a stand mixer fitted with the paddle attachment, beat butter, granulated sugar, and lemon zest at medium speed until light and fluffy, 3 to 4 minutes, stopping to scrape bottom and sides of bowl. Add eggs, one at a time, beating well after each addition. Beat in vanilla.
In a medium bowl, whisk together 2⅓ cups (292 grams) flour, salt, and baking soda. With mixer on low speed, gradually add flour mixture to butter mixture alternately with buttermilk, beginning and ending with flour mixture, beating until just combined after each addition and stopping to scrape bottom and sides of bowl.
In small bowl, toss together blueberries and remaining 2 tablespoons (16 grams) flour until coated. Using a rubber spatula, fold blueberry mixture into batter until well combined.
Spray a 10-cup Bundt pan with baking spray with flour. Spoon batter into prepared pan, gently spreading with an offset spatula.
Bake until a wooden pick inserted near center comes out clean, 1 hour to 1 hour and 5 minutes. Let cool in pan on a wire rack for 15 minutes. Invert cake onto a wire rack. Garnish with confectioners’ sugar, if desired, and serve warm, or let cool completely. Store in an airtight container for up to 3 days.