Step 1: Prep the Oven and Pan
Preheat your oven to 350°F (175°C). Grease a 9-inch springform pan or round cake pan with butter, then line the bottom with a circle of parchment paper. Pro Tip: A light dusting of flour over the greased sides prevents sticking and helps the cake climb the edges evenly, resulting in a perfectly flat top.Step 2: Cream the Butter and Sugar
In a large mixing bowl, use a hand mixer or stand mixer to beat the softened unsalted butter and granulated sugar on medium-high speed for about 3-4 minutes. You are looking for a pale, fluffy texture. Beat in the eggs one at a time, followed by the vanilla extract and lemon zest. Actionable Tip: Do not rush the creaming process. Whipping air into the butter is what gives your blueberry cake its signature light and moist crumb.Step 3: Whisk and Alternate the Dry Ingredients
In a separate medium bowl, whisk together the all-purpose flour, baking powder, and salt. Reduce your mixer speed to low. Gradually add the dry ingredients to the wet butter mixture in three additions, alternating with the sour cream (or Greek yogurt). Begin and end with the flour mixture. Mix just until combined to avoid overworking the gluten.Step 4: The Crucial Blueberry Fold
Take your fresh blueberries and toss them in 1 tablespoon of flour. Gently fold the flour-coated berries into the batter using a silicone spatula. Actionable Tip: Tossing the berries in flour creates a microscopic friction layer, suspending them in the batter so they don't sink to the bottom during the baking process.Step 5: Bake to Golden Perfection
Pour the thick batter into your prepared pan, smoothing the top with your spatula. Bake on the middle rack for 40 to 45 minutes. You will know it is done when the top is golden brown and a toothpick inserted into the center comes out clean (or with a few moist crumbs attached). Let the cake cool in the pan for 15 minutes before transferring it to a wire rack.
