Preheat your oven to 350°F (175°C). Prepare a 9-by-9-inch baking pan by lining it with aluminum foil and spraying it with cooking spray, or greasing and flouring the pan. This ensures your cake will come out easily once baked.
In a large mixing bowl, crack in the 2 large eggs and add the Greek blueberry yogurt, granulated sugar, canola oil, lemon zest (if using), and vanilla extract. Use a whisk to combine all ingredients until smooth and well-blended. The mixture should be creamy and homogeneous.
Gradually add in the all-purpose flour and baking powder. Mix gently until just combined—be careful not to overmix, as this can lead to a denser cake.
Now it’s time to fold in the frozen blueberries. Use a spatula to gently stir them into the batter, ensuring they’re evenly distributed without breaking apart. Remember, frozen blueberries are perfect as they won’t bleed into the batter.
Pour the batter into your prepared pan, spreading it evenly. Before baking, sprinkle the remaining 1/4 cup blueberries on top of the batter for added visual appeal and flavor.
Place the pan in the preheated oven and bake for approximately 37 to 40 minutes. The cake is done when the top is domed and set, and a toothpick inserted into the center comes out clean. The edges should just start to pull away from the sides of the pan, indicating it's perfectly baked.
Once baked, allow the cake to cool in the pan for at least 15 minutes. Then, carefully turn it out onto a wire rack to cool completely. This cooling process is crucial for achieving the right texture.
While your cake is cooling, prepare the glaze. In a small bowl, combine the lemon juice, confectioners' sugar, and the remaining vanilla extract. Whisk until smooth, adjusting the consistency by adding more lemon juice or sugar as needed.
Finally, drizzle the glaze over the cooled cake. This sweet topping adds the finishing touch and enhances the cake’s flavor. Serve immediately or store in an airtight container at room temperature or in the refrigerator for up to 5 days.
