Preheat oven to 350F and line three 8” round cake pans by lightly but thoroughly greasing and flouring the sides and lining the bottoms with parchment paper. Set aside.

In a large bowl, whisk together flour, sugar, cornstarch, baking powder, baking soda, and salt.

Using an electric mixer, add softened butter, one tablespoon at a time, adding the next tablespoon only after the first is combined. The mixture will appear sandy in texture.

While mixing on low-speed, slowly drizzle in oil.

In a separate bowl or large measuring cup, whisk together buttermilk, lemon zest, lemon juice, eggs, and vanilla extract until combined.

With mixer on low-speed, slowly drizzle in the buttermilk mixture until the batter is smooth and completely combined.

Use a spatula to stir in blueberries.

Evenly divide batter into prepared cake pans and transfer to 350F oven (if your oven is not large enough for all three pans or if you only have two pans, it is fine to let the remaining batter sit on the counter while the first two pans bake. If all of your pans do fit in the oven, make sure to keep an eye on them as most ovens do not cook evenly and some pans may be done sooner than others). Bake for 30 minutes or until the surface of the cake springs back to the touch and a toothpick inserted in the center comes out mostly clean with a few moist crumbs.

Allow cakes to cool in cake pans for 10-15 minutes before running a knife around the edge of the pan to loosen cakes and carefully inverting onto a cooling rack to cool completely before decorating.

Once cooled completely, decorate the cake using lemon frosting (or preferred frosting).