
Preheat the oven to 350°F.
In a large bowl, stir together blueberries, sugar, and lemon zest until combined. Set aside.
Place the butter in a 8x8-inch baking dish. Place the dish in the preheated oven until the butter is melted, about 10 minutes.
Meanwhile, in a medium mixing bowl, whisk together the flour, sugar, baking powder, and salt. Whisk in the milk until just combined.
Carefully remove the baking dish from the oven, and pour the batter into the pan (do not stir). Top evenly with the blueberry mixture. Sprinkle with coarse sugar.
Bake for 40 to 45 minutes or until the batter is golden brown and a wooden pick inserted in the center comes out mostly clean. Let the cobbler cool slightly before serving. Serve with a scoop of vanilla ice cream, if desired.