lemon zest, grated
- Preheat the oven to 350°F Butter and flour an 8" x 2" round cake pan.
- In a small bowl, stir 1 tablespoon of the lemon juice into 1/2 cup of the milk and set aside.
- In another bowl, stir together the flour, poppyseeds, baking soda and salt.
- In another bowl, cream the butter and 1 cup of the granulated sugar.
- Beat in the whole eggs one at a time.
- Beat in 1 teaspoon of the lemon zest (if using) and the lemon extract.
- Alternately beat in the dry ingredients and the lemon juice/ milk mixture.
- Pour the batter into the pan and bake for 35 to 40 minutes, or until a toothpick inserted in the center comes out clean.
- Cool the cake in the pan on a rack for 10 minutes.
- Remove from the pan to cool completely.
- Meanwhile, in a small saucepan, combine the remaining 1/3 cup granulated sugar with the 1 1/2 teaspoon cornstarch and remaining 1/4 cup milk.
- Cook over medium heat, stirring until thickened-- about 3 to 4 minutes.
- In a small bowl, beat the egg yolk.
- Beat in about 2 tablespoons of the hot cornstarch/ milk mixture.
- Stir the warmed yolk mixture into the saucepan and cook over medium heat for 1 to 2 minutes.
- Remove the pan from the heat and stir in the remaining 2 teaspoons lemon juice and 1 teaspoon lemon zest (if using).
- Loosely cover the custard with waxed paper and let cool to room temperature.
- In a mixing bowl, beat the heavy cream until soft peaks form.
- Fold the whipped cream into the cooled lemon custard in the saucepan.
- With a long serrated knife, split the cake in half horizontally.
- Spread all of the lemon filling over the cut side of the bottom layer.
- Top with the remaining layer, cut-side down, and dust the cake with the confectioner's sugar.