Preheat oven to 400°. Place a baking sheet in oven to preheat.
In a medium bowl, using a rubber spatula, mix cream cheese, confectioners’ sugar, lemon zest, and lemon juice until combined.
In a bowl, coat blueberries in juice of the other ½ of the lemon and 2 tbsp sugar, set aside.
In another medium bowl, rub granulated sugar and lemon zest with your fingers until fragrant; mix in flour. Add butter and stir until combined.
On a piece of parchment, roll pastry to a 12x19 rectangle. Fold in sides about ¼" all the way around to create a border.
Spread cream cheese layer in center of pastry up to border. Spoon blueberry layer over cream cheese. Sprinkle crumble over. Very carefully slide parchment onto preheated sheet.
Bake tart until pastry is golden brown and puffed and blueberries are bursting, 20 to 25 minutes. Let cool 10 minutes before slicing.
