Preheat your oven to 350°F (175°C). Grease your 9x13-inch baking dish with a little butter or non-stick spray.
In a large mixing bowl, whisk together the flour, sugar, baking powder, and salt until well combined.
Gradually stir in the milk and melted butter until the batter is smooth. The mixture will be thick.
Fold in the lemon zest for added flavor.
Pour the batter into the prepared baking dish. Do not worry about spreading it evenly; it will spread during baking.
In a separate bowl, mix together the lemon juice and an additional 1 cup of sugar. Stir until the sugar is dissolved.
Slowly pour the lemon juice mixture over the batter in the baking dish. Do not stir; it will create two layers while baking.
Bake in the preheated oven for about 40 minutes, or until the top is golden brown and set.
Allow the cobbler to cool for a few minutes before serving. If desired, dust with additional sugar for garnish.