Preheat your oven to 325°F (163°C). Grease and flour a 9×5-inch loaf pan or a bundt pan to prevent sticking. You can also line the pan with parchment paper for added safety.

In a large mixing bowl, beat the softened butter and granulated sugar together using an electric mixer on medium speed until light, fluffy, and pale yellow, about 4-5 minutes.

Add eggs one at a time, beating well after each addition to ensure they are fully mixed in.

In a separate bowl, whisk together flour, baking soda, and salt to ensure they are evenly distributed.

Whisk together sour cream, lemon juice, lemon zest, and vanilla extract in a medium bowl. Gradually add the dry ingredients to the butter mixture, alternating with the sour cream mixture, starting and ending with the dry ingredients.

Mix until just combined to avoid overmixing.

Toss the blueberries with 2 tablespoons of flour to coat them lightly to help keep them from sinking in the cake.

Gently fold the floured blueberries into the batter with a spatula, being careful not to crush them.

Pour the batter into the prepared pan and smooth the top with a spatula.

Bake for 70-80 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs.

Let the cake cool in the pan for 15 minutes, then transfer it to a wire rack to cool completely.

Prepare the glaze by whisking powdered sugar, lemon juice, lemon zest, and milk/heavy cream until smooth.

Drizzle the glaze over the cake and let it set before slicing.