Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking dish and line it with parchment paper, leaving some overhang on the two longer sides to make lifting the cake out easier once it’s baked.

In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside. In the bowl of a stand mixer fitted with the paddle attachment (or using a hand mixer), cream the softened butter and granulated sugar together until light and fluffy. Add the eggs, vanilla extract, and buttermilk, mixing on low speed until fully combined. Gradually add the dry ingredients and mix just until no streaks of flour remain. Stir in the lemon zest and juice, then gently fold in the flour-coated blueberries with a spatula.

Pour the batter into the prepared baking dish and smooth the top. Bake for 40–45 minutes, or until a toothpick inserted in the center comes out with only a few moist crumbs. Allow the cake to cool completely in the pan. You can either lift the cake out using the parchment overhang to drizzle and slice, or keep it in the pan for serving—either method works well.

To make the glaze, whisk together the powdered sugar and lemon juice until smooth, then drizzle evenly over the cooled cake. Let the glaze set before garnishing with fresh fruit and serving.