Preheat oven to 350°F and grease a 9-inch cake pan or pie dish.

In a large bowl, cream together butter and sugar. Add egg, vanilla, lemon zest, and lemon juice. Mix until smooth.

In a separate bowl, combine flour, baking powder, and salt. Gradually add to wet ingredients and stir just until combined.

Transfer the batter to the prepared pan and spread evenly.

For the cream layer: Beat softened cream cheese until smooth. Gradually mix in powdered sugar, then add egg and lemon zest. Mix until creamy.

Spread cream mixture over the cake batter in an even layer.

Bake for 38-40 minutes, or until golden brown and center is set. Let cool completely before slicing.

Optional: Dust with powdered sugar before serving.