Preheat the oven to 350°F and grease your cake pan well. I like lining the bottom with parchment for easy release. This step ensures the cake doesn’t stick and bakes evenly.
In a bowl, whisk together flour, baking powder, and salt. Mixing them first helps distribute the leavening evenly. It also prevents clumps in the batter later.
Beat the butter and sugar until light and fluffy. This step adds air to the batter, making the cake soft. I usually mix for about three minutes.
Add eggs one at a time, mixing well after each. Then blend in lemon zest, lemon juice, and vanilla. The batter will smell amazing at this stage.
Combine Wet and Dry Ingredients
Alternate adding the dry mixture and milk into the batter. Start and end with dry ingredients. This keeps the batter smooth and prevents overmixing.
Toss blueberries with a tablespoon of flour. This small step keeps them from sinking. Gently fold them into the batter using a spatula.
Pour the batter into the pan and smooth the top. Bake for about 55–60 minutes until a toothpick comes out clean. Let it cool before removing.