Preheat the oven to 350 degrees F (175 degrees C). Butter six 4-inch ramekins and place in a 9x13-inch baking pan.

Combine blueberries, 2 tablespoons white sugar, and lemon zest in a small bowl; set aside.

Microwave 2 tablespoons butter in a microwave-safe bowl until melted, about 30 seconds; stir in brown sugar. Divide brown sugar butter among bottoms of each ramekin. Divide blueberry mixture among ramekins.

Beat ½ cup butter and ½ cup white sugar in a large bowl with an electric mixer until fluffy. Beat in eggs, one at a time, beating well after each addition. Beat in lemon juice and vanilla extract. Add flour, baking powder, ginger, and salt; beat to combine. Beat in milk. Divide batter among ramekins on top of blueberry mixture.

Bake in the preheated oven until a toothpick inserted into the centers comes out clean, 25 to 35 minutes.