Preheat your oven to 375°F (190°C).
In a large bowl, mix together the blueberries, 1/2 cup sugar, 2 tablespoons flour, and lemon juice. Pour the mixture into an 8x8 inch baking dish.
In a separate bowl, whisk together 1 cup flour, 2 tablespoons sugar, baking powder, and salt.
Using a pastry cutter or your fingers, cut the butter into the flour mixture until it resembles coarse crumbs.
Add the milk and vanilla extract (if using) to the flour mixture, and stir until just combined.
Using a spoon, drop spoonfuls of the batter onto the blueberry mixture in the baking dish.
Bake for 35-40 minutes, or until the topping is golden brown and the blueberry filling is bubbling.
Let the cobbler cool for 10-15 minutes before serving. Serve warm with ice cream, whipped cream, or your favorite toppings.