Ingredients

Cake:

Vegetable oil cooking spray

1 ½ cups cake flour (not self-rising), sifted

1 tablespoon baking powder

½ teaspoon salt

½ cup plus 2 tablespoons granulated sugar

½ cup skim milk

1/3 cup canola oil

1 ½ teaspoons pure vanilla extract

Finely grated zest of 1 lemon, plus 1 teaspoon fresh lemon juice

4 large egg whites, room temperature

1 tablespoon confectioners’ sugar

Lemon curd:

4 large egg yolks, lightly beaten

Finely grated zest of ½ lemon, plus ½ cup fresh lemon juice

1 1/3 cups granulated sugar

1/3 cup cornstarch

Pinch of salt

1 teaspoon pure vanilla extract

1 1/3 cups blueberries, lightly crushed

Preparation

Cake:

  1. Preheat oven to 350° F. Coat two 8-by-1 1/2-inch round cake pans with cooking spray. Line bottoms with parchment. Spray parchment; set aside.

  2. Sift together flour, baking powder, & salt into a medium bowl; set aside. Whisk together 1/4 cup sugar, milk, oil, vanilla, lemon zest, & lemon juice in a large bowl; set aside.

  3. Put egg whites in the bowl of an electric mixer fitted with whisk attachment. Beat on medium speed until foamy. Raise speed to medium-high. Gradually add remaining 1/4 cup plus 2 tablespoons sugar, beating until stiff peaks form.

  4. Add half of the flour mixture to the milk mixture; whisk until smooth. Fold in remaining flour mixture in 3 batches, alternating with the egg white mixture. Divide batter among prepared pans. Bake, rotating pans halfway through, until a cake tester inserted into centers comes out clean, about 18 minutes. Let cool on a wire rack for 10 minutes. Turn out cakes onto rack. Remove parchment; reinvert. Let cool completely.

Lemon curd: 5. Make the lemon curd: Put egg yolks into a medium heatproof bowl; set aside. Whisk together lemon zest, sugar, cornstarch, & salt in a medium saucepan. Add 1 1/2 cups water & the lemon juice; whisk until sugar & cornstarch have dissolved. Bring to a boil over medium-high heat, whisking constantly. Cook 2 minutes. Reduce heat to medium-low; gradually whisk one-third of the lemon mixture into the reserved egg yolks. Pour mixture into pan. Cook over medium heat, stirring constantly, 2 1/2 minutes.

  1. Remove from heat. Stir in vanilla. Pour into a bowl; place plastic wrap directly on surface. Refrigerate until firm & cold, at least 1 hour (up to 1 day).

Finish: 7. Fold blueberries into curd; set aside. Trim top & bottom of one cake to be flat. Cut each cake in half horizontally. Set untrimmed bottom layer on a serving plate; spread with 1 cup curd. Repeat with trimmed halves for second & third layers. Top with untrimmed top layer. Dust with confectioners’ sugar.