Place oven rack in center position. Preheat oven to 325 degrees F. Use a paper towel to wipe sides of cake pan with butter. Cut a circle of parchment paper to fit in the bottom of pan, set aside.

In a small bowl, whisk together: flour, baking powder, and salt. Set aside.

Place granulated sugar and lemon zest in a large bowl, whisk. Add olive oil, buttermilk, eggs, and vanilla, whisk until combined. Add lemon juice and whisk. Add dry ingredients, whisking until well incorporated and batter is smooth. Gently fold in blueberries. Pour batter into parchment lined pan. Bake for 45-50 minutes or until an inserted toothpick comes out clean.

Remove from oven and immediately use a knife to separate cake from the edges of pan. Allow to cool. Flip pan, remove cake, peel parchment off bottom of cake and place on cake plate. Use a screen colander of sifter to sprinkle cake with powdered sugar. Enjoy!