In a medium saucepan over medium heat, combine fresh or frozen blueberries, sugar, cornstarch, and lemon juice. Bring to a gentle boil, stirring frequently until it thickens, about 4-8 minutes. Cool and chill in the fridge.

In a mixing bowl, beat cream cheese with powdered sugar using an electric mixer until smooth, about 2-3 minutes. Fold in whipped topping until combined. Refrigerate until ready.

Soak ladyfinger cookies briefly in milk for 2-3 seconds, then lay half in an 8x8 inch dish to form the base.

Spread half of the cooled blueberry filling over ladyfingers, followed by half of the cheesecake filling.

Repeat with another layer of ladyfingers, remaining blueberry filling, and then the remaining cheesecake filling on top.

Cover with plastic wrap and refrigerate for at least 6 hours, preferably overnight.

Cut into squares, garnish with white chocolate, and serve chilled.