°1 c (224 g) granulated sugar
°zest 1 lemon, peeled to rounds. You only want the yellow part, not the bitter white pith.
°1/2 cup (1 stick or 113 g) butter at room temperature
°2 large eggs, at room temperature
°1 teaspoon vanilla extract
°1 3/4 cup all-purpose flour
°1/4 cup cornstarch
°2 teaspoons baking powder
°1 teaspoon of salt
°/2 cup cultured buttermilk
°2 cups of fresh blueberries
Preheat the oven to 350F. Lightly grease & line a 9×9 inch square pan with paper.
First prepare the lemon sugar. Place the sugar and lemon zest in a food processor and process until the zest is completely incorporated into the sugar and is pale yellow and fragrant.
Whisk the sugar and butter until pale and fluffy, I like to go for a full 5 minutes, scraping the bowl as needed. I do this in a stand mixer.
Hit the eggs one at a time. Beat each one well and scrape that bowl! Stir in vanilla.
Whisk together flour, cornstarch, baking powder and salt.
Take about a tablespoon of the flour mixture and mix with the blueberries. Then add the rest to the blender and blend until almost incorporated. Then stir in the buttermilk until just combined, but don’t overdo it. Gently fold the blueberries.
Place batter (it will be thick) in prepared pan and spread evenly. Bake for about 40 minutes, or until browned and a toothpick inserted in the center comes out without the moist dough sticking to it. I like to cover the cake loosely near the end of baking to keep it from over browning.
Let the cake cool for at least 15 minutes before cutting it.