Preheat oven to 350°. Spray 1 (9-inch) cast-iron skillet or 3 (6-inch) cast-iron skillets with cooking spray.
For cake: In a large bowl, beat butter and sugar with a mixer at medium speed until fluffy, 3 to 4 minutes, stopping to scrape sides of bowl. Add eggs, one at a time, beating well after each addition. Stir in zest and vanilla.
In a medium bowl, whisk together flour, salt, and baking powder. Gradually add flour mixture to butter mixture alternately with sour cream, beginning and ending with flour mixture, beating just until combined after each addition. Fold in 1 cup blueberries. Divide batter among prepared skillets. Press remaining 1⁄4 cup blueberries into top of batter.
Bake until a wooden pick inserted in centers comes out clean, 25 to 30 minutes. Let cool completely.
For glaze: In a medium bowl, whisk together confectioners’ sugar, milk, and lemon zest and juice. Drizzle over cooled cakes.
Recipe by Taste of the South at https://tasteofthesouthmagazine.com/blueberry-lemon-pound-cake/