Preparation

• Preheat the oven to 335°. Line a 9" springform pan with parchment paper and grease the sides of the pan.
• In a large mixing bowl, toss together the washed and dried blueberries and cornstarch until the berries are well coated. Set aside.
• In a large mixing bowl, cream together the butter, sugar, vanilla and lemon zest until light and fluffy, about 3 minutes. Add the eggs, one at a time, and mix well after each addition.
• Press the cup of cottage cheese through a sieve, scraping off of the bottom of the sieve. Add the cottage cheese to the creamed ingredients and mix again until batter is mostly creamy. (If using ricotta cheese, just add it directly to the butter mixture.)
• In a separate bowl, combine the flour, baking powder, and salt. Remove the creamed mixture bowl from the stand mixer and sift the dry ingredients into the batter, then fold with a spatula just until combined.
• Gently stir in the lemon juice, if using (highly recommended). Add 2 ½ cups of the blueberries to the batter and fold them in.
• Transfer the batter into the prepared pan and spread the batter evenly to the edges. Add the remaining ½ cup of blueberries over the top, pressing them down lightly.
• Bake the cake in the preheated oven for 1 hour and 10 minutes to 1 hour and 30 minutes, or until a toothpick inserted into the center comes out clean.
• Remove the cake from the oven and cool for 10 minutes in the pan. Remove cake from the springform pan and peel off the parchment paper. Finish cooling on a rack. Dust about 1 tablespoon of powdered sugar over the top of the cake after cooled. Serve it warm or cool.