until a toothpick inserted into the center comes out clean.
Prepare the Lemon Pudding:
Cook the Pudding:
In a saucepan, whisk together the egg, sugar, vanilla extract, and cornstarch.
Add the milk and lemon zest, and cook over medium heat, stirring constantly, until the mixture comes to a boil and thickens.
Finish with Butter and Lemon Juice:
Once thickened, remove from heat and stir in the butter and an additional tablespoon of lemon juice.
Serve:
Allow the cake to cool slightly after baking. Then, slice and serve with the warm lemon pudding poured over each piece.