Step 1: Preheat the oven to 175°C (350°F). Grease and flour a 10-inch bundt or loaf pan, or line with parchment paper.

Step 2: In a large bowl, cream the softened butter and granulated sugar together using a hand or stand mixer until light and fluffy, about 3–4 minutes.

Step 3: Add eggs one at a time, beating well after each addition. Mix in vanilla extract and lemon zest.

Step 4: In a separate bowl, whisk together flour, baking powder, baking soda, and salt.

Step 5: Add the dry ingredients to the butter mixture in three parts, alternating with buttermilk, beginning and ending with the flour mixture. Mix until just combined.

Step 6: Gently fold in the blueberries to avoid breaking them.

Step 7: Pour the batter into the prepared pan and smooth the top with a spatula.

Step 8: Bake in the preheated oven for 60–70 minutes, or until a toothpick inserted into the center comes out clean.

Step 9: Allow the cake to cool in the pan for 10–15 minutes, then remove it and place it on a wire rack to cool completely.

Step 10: Prepare the glaze by whisking together powdered sugar, lemon juice, and lemon zest until smooth. Adjust the consistency by adding more sugar or juice if needed.

Step 11: Drizzle the glaze over the cooled cake and allow it to set before slicing.