Very Blueberry Cake
- 2 cups cake flour*
- 2 teaspoons baking powder
- 2 sticks unsalted butter, soft
- 1 1/2 cups Imperial Sugar Extra Fine Granulated Sugar
- 8 large egg yolks, room temperature
- 3/4 teaspoon salt
- 1 tablespoon vanilla extract
- 2 teaspoon lemon zest
- 3/4 cup buttermilk, room temperature
- 1 1/4 cups fresh blueberries (not frozen and room temperature)
- 2 1/3 cups frozen blueberries (do not use fresh)
- 4 sticks (1 pound) unsalted butter, very soft
- 2 cups Imperial Sugar Extra Fine Granulated Sugar
- 2 cups frozen blueberries (do not use fresh)
- 4 tablespoons Imperial Sugar Extra Fine Granulated Sugar
- Juice of 1 lemon
- 1 tablespoon cornstarch
- 1 tablespoon water
- *Spoon & Sweep method: Use a spoon to fill measuring cup with flour until required amount is obtained. Scooping measuring cup directly into flour bag will firmly pack flour resulting in too much flour required for recipe.
- Preheat oven to 350°F.
- Butter and flour two 8 or 9-inch baking pans and set aside. (Fitting a round piece of parchment paper on bottom of baking pan is necessary as blueberries will bleed and otherwise stick to the pan.)
- Sift together flour and baking powder and set aside.
- Mix butter until very creamy and smooth. Add sugar and mix until light and fluffy. Add one egg yolk at a time and mix at least 30 seconds between each.
- Add salt, vanilla extract, and lemon zest. Mix for another 3 minutes to ensure mixture is light and fluffy. If it is cold and dense, use a hairdryer to heat sides of bowl while mixing.
- Add one third of flour and mix until combined. Add half of buttermilk and mix until smooth. Add another one third of flour and mix until smooth. Add remaining buttermilk and once combined add remaining flour. Add blueberries.
- Divide batter into pans and place in oven and bake for 30-35 minutes until center of cake bounces back when lightly pressed with a finger or until an inserted toothpick comes clean.
- After 10 minutes turn upside down on plastic food lined surface and allow to cool completely before frosting, about 1 hour. Do not peel parchment paper off cake layers.
- For frosting, defrost blueberries in microwave or at room temperature. Using a stick or stand blender puree berries until very smooth. Set aside.
- Mix butter until creamy. Add sugar and keep mixing until light and fluffy. If mixture is cold and dense, use a hairdryer to heat sides of bowl while mixing.
- Add pureed (room temperature) blueberries in 7-8 increments, beating cream very well in between additions. If needed, heat frosting with hairdryer. The frosting should be light and fluffy.
- Place a cooled cake layer parchment paper side up on a serving platter. Remove parchment paper.
- Spread a generous amount of frosting on cake layer and top with second cake layer parchment paper side up. Remove paper.
- Frost cake on sides and surface keeping some frosting for rosettes.
- Place remaining frosting in a piping bag fitted with a small star tip and pipe a circle of rosettes on cake.
- For blueberry topping, place blueberries and sugar in a saucepan.
- Squeeze lemon and add enough water to obtain 1/3 cup total liquid. Pour into saucepan and bring to a boil.
- Mix cornstarch with 1 tablespoon water and add to mixture once it is boiling.
- Boil until it makes bubbles and has thickened, remove from heat. Let cool completely before spreading onto cake.
- Serve at room temperature that is when cake is at its best and frosting is most creamy.
For a smooth and creamy buttercream frosting, all ingredients should be at the same temperature. If your liquid was not at room temperature the mixture cannot homogenize and will take on a curdled appearance (become soupy looking). This is a sign that the mixture is still too cold. Rapidly stirring and gentle warming will emulsify the buttercream to a smooth and creamy consistency. Continue to mix while using a hair dryer on the outside of mixing bowl until the perfect consistency is reached. For additional tips on how to make the perfect buttercream, watch our How to Fix a Broken Buttercream video.