From Elise: Although the cake was delicious, I'm beginning to think that fresh blueberries are best eaten fresh. If we can't tell the difference after cooking between fresh or frozen blueberries, we may as well use frozen for baked goods. Trader Joe's sells good quality frozen blueberries (Lucky people who have a Trader Joe's near them!) and for less than what you will pay for fresh, even in season.
1 cup plus 1 teaspoon of all purpose flour
1 teaspoon baking powder
1/2 teaspoon kosher salt
4 oz (1 stick) unsalted butter, softened
1 cup sugar
1/4 teaspoon vanilla
2 large eggs
2 cups blueberries, rinsed and drained (may substitute frozen blueberries, or substitute some of the blueberries for raspberries)
1 teaspoon lemon juice
Preheat oven to 350°F. Lightly grease a 9-inch springform pan and dust with flour. Or use a 9-inch round cake pan that has been greased and dusted with flour and lined on the bottom with parchment paper. In a small bowl combine 1 cup of flour with the baking powder and salt and set aside.
Using a mixer, cream the butter, sugar and vanilla until light and fluffy, about 3 minutes. Add the eggs one at a time and beat until well blended. Reduce the speed of the mixer to low and gradually add the flour mixture. Beat until smooth. Pour the batter into the baking pan.
In a medium bowl, combine the berries with the remaining teaspoon of flour and the lemon juice. Spoon the berry mixture over the batter.
Bake for 1 hour at 350°F, or until a toothpick inserted into the center comes out clean. Remove from the oven and let the cake cool in the pan for 10 minutes. If using a springform pan, slide a thin knife around the edges of the cake to release it from the pan before you release and remove the springform. If using a cake pan, slide a thin knife around the edges of the cake and invert it onto a cake rack. Transfer the cake to a platter, berry side up. Dust the cake with confectioner's sugar before serving.