Preheat oven to 320°F (160°C) and line muffin tin with cupcake liners.

Melt cream cheese, butter, and milk over low heat until smooth. Let cool slightly.

Beat egg yolks, half sugar, lemon juice, and vanilla into cream cheese mixture. Sift in flour and cornstarch and mix.

Beat egg whites until foamy. Gradually add remaining sugar and beat until stiff peaks form.

Gently fold egg white meringue into cream cheese batter in three additions.

Pour batter into cupcake liners, filling ¾ full. Bake 18–22 minutes until lightly golden and toothpick comes out clean.

Cool in tin 10 minutes, transfer to wire rack, dust with powdered sugar before serving.