Preheat your oven to 350°F (175°C). Grease a 9-inch cake pan and line the bottom with parchment paper for easy removal.
Mix the Dry Ingredients
In a medium bowl, whisk together the flour, baking powder, and salt. Set aside.
Beat the Eggs and Sugar
In a large bowl, beat the eggs and sugar using a whisk or electric mixer until thick, pale, and fluffy (about 2-3 minutes).
Heat the Milk and Butter
In a small saucepan, heat the milk and butter over medium heat until the butter melts and the mixture is hot but not boiling. Remove from heat and stir in the vanilla extract.
Combine Wet and Dry Ingredients
Gradually fold the dry ingredients into the egg mixture using a spatula. Once combined, slowly pour the hot milk mixture into the batter, stirring gently but consistently until smooth.
Add the Blueberries
Toss the blueberries with the sugar and lemon juice. Gently fold half of the blueberry mixture into the batter.
Bake the Cake
Pour the batter into the prepared pan and scatter the remaining blueberries on top. Bake for 30-35 minutes, or until a toothpick inserted in the center comes out clean.
Cool and Serve
Let the cake cool in the pan for 10 minutes, then transfer to a cooling rack. Dust with powdered sugar before serving, and garnish with whipped cream or vanilla ice cream if desired.