Ingredients:

• For the Cake:
  • 3 cups (375g) all-purpose flour
  • 1 ½ cups (300g) granulated sugar
  • 1 tablespoon cornstarch
  • 2 teaspoons baking powder
  • ½ teaspoon baking soda
  • ½ teaspoon salt
  • ½ cup (113g) unsalted butter, softened, cut into 8 pieces
  • ½ cup (120ml) oil (canola, vegetable, or avocado oil)
  • ¾ cup (180ml) buttermilk
  • 2 tablespoons lemon zest
  • ¼ cup (60ml) fresh lemon juice
  • 4 large eggs (preferably room temperature)
  • ½ teaspoon vanilla extract
  • 2 ½ cups (340g) blueberries (fresh or frozen)
• For the Frosting:
  • 1 batch lemon frosting (or your preferred frosting)

Instructions:

1. Prepare the pans: Preheat your oven to 350°F (175°C). Grease and flour three 8-inch round cake pans, and line the bottoms with parchment paper. Set aside.
2. Mix the dry ingredients: In a large bowl, whisk together the flour, sugar, cornstarch, baking powder, baking soda, and salt.
3. Incorporate the butter: Using an electric mixer, add the softened butter, one tablespoon at a time, mixing thoroughly between each addition. The batter will have a sandy texture.
4. Add the oil: With the mixer on low speed, slowly drizzle in the oil, allowing it to combine with the butter mixture.
5. Mix the wet ingredients: In a separate bowl or large measuring cup, whisk together the buttermilk, lemon zest, lemon juice, eggs, and vanilla extract.
6. Combine the wet and dry ingredients: With the mixer on low speed, slowly add the buttermilk mixture to the dry ingredients. Mix until the batter is smooth and fully combined.
7. Fold in the blueberries: Gently stir the blueberries into the batter with a spatula.
8. Bake the cakes: Divide the batter evenly between the prepared pans. Bake for 30 minutes or until the cake tops spring back when lightly touched and a toothpick inserted comes out mostly clean with a few moist crumbs. If your oven doesn’t fit all three pans at once, bake in batches.
9. Cool the cakes: Let the cakes cool in their pans for 10-15 minutes. Use a knife to loosen the edges, then carefully invert the cakes onto a cooling rack to cool completely before frosting.
10. Frost the cake: Once the cakes have cooled completely, frost with the lemon frosting or your preferred frosting.

Notes:

• Blueberries: Fresh blueberries are ideal, but frozen blueberries can be used without thawing. If using wild blueberries, be aware that they might streak the batter with purple.
• Storage: Keep the cake tightly covered at room temperature for up to 24 hours, or refrigerate in an airtight container for up to 5 days. Note that refrigerating may slightly dry out the cake over time.