1. Prepare the Oven and Baking Pan: Setting the Stage for Baking

1. Preheat Oven: Preheat your oven to 350°F (175°C).
2. Grease Pan: Grease an 8-inch or 9-inch square baking pan with butter or non-stick cooking spray.
   • Tip: The recipe author prefers an 8-inch pan for thicker pieces of cake.
3. Line with Parchment (Optional): For easier removal, line the bottom of the pan with parchment paper, leaving an overhang on two sides. Grease the parchment paper as well.

2. Prepare the Blueberries (if using fresh): Preventing Sinking

1. Toss with Flour: If using fresh blueberries, toss them with ¼ cup of the measured flour in a small bowl. This helps to prevent them from sinking to the bottom of the cake during baking.
   • Note: If using frozen blueberries, do not thaw, and do not toss in flour.

3. Combine Dry Ingredients: Ensuring Even Distribution

1. Whisk Together: In a medium bowl, whisk together the remaining 1 ¾ cups of flour, 2 teaspoons of baking powder, and 1 teaspoon of kosher salt (or 1 ¼ teaspoons, to taste). Set aside.

4. Cream Together Butter, Lemon Zest, and Sugar: The Foundation of Flavor

1. Combine: In a large mixing bowl, combine the softened butter, lemon zest, and 1 cup minus 1 tablespoon of granulated sugar.
2. Cream: Using an electric mixer (handheld or stand mixer), beat the mixture on medium-high speed until it’s light and fluffy, about 3-4 minutes. This incorporates air into the batter, resulting in a tender cake.

5. Incorporate Egg and Vanilla: Adding Moisture and Flavor

1. Add Egg: Add the egg to the creamed butter and sugar mixture. Beat well until fully incorporated.
2. Add Vanilla: Stir in the vanilla extract and mix until combined.

6. Alternate Adding Dry Ingredients and Buttermilk: Achieving the Perfect Texture

1. Begin and End with Dry: With the mixer on low speed, gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk. Begin and end with the dry ingredients.
   • Example: Add about ⅓ of the dry ingredients, mix until just combined, then add ½ of the buttermilk, mix again, and repeat, ending with the final ⅓ of the dry ingredients.
   • Tip: Don’t overmix the batter. Mix only until the ingredients are just combined and no streaks of flour remain.

    

7. Fold in Blueberries: Adding Bursts of Juicy Sweetness

1. Gently Fold: Using a rubber spatula, gently fold in the flour-coated blueberries (or frozen blueberries) until they are evenly distributed throughout the batter.
   • Tip: Be careful not to overmix, as this can crush the blueberries and make the batter too wet.

8. Bake the Cake: Achieving a Golden-Brown Top

1. Pour Batter into Pan: Pour the batter into the prepared baking pan and spread it evenly with a spatula.
2. Sprinkle with Sugar: Sprinkle the remaining 1 tablespoon of granulated sugar evenly over the top of the batter. This will create a slightly crunchy, sweet crust.
3. Bake: Bake in the preheated oven for 35 to 45 minutes.
   • Note: A 9-inch pan will likely be done closer to 35 minutes, while an 8-inch pan may need closer to 40-45 minutes, or longer.
4. Check for Doneness: The cake is done when a wooden toothpick inserted into the center comes out clean, or with just a few moist crumbs attached. The top should be golden brown.
   • Tip: If the top starts to brown too quickly, loosely cover the pan with aluminum foil for the last 10-15 minutes of baking.
   • Note: The recipe author notes that baking for as long as 50 minutes, or even longer, might be necessary. Don’t be afraid to let it bake longer.

9. Cool and Serve: Enjoying Your Blueberry Breakfast Cake

1. Cool in Pan: Remove the baking pan from the oven and let the cake cool in the pan for at least 15 minutes before serving. This allows it to firm up slightly.
2. Serve Warm or at Room Temperature: You can serve the cake warm, directly from the pan, or let it cool completely on a wire rack before slicing and serving.