Preheat the Oven: Preheat your oven to 350°F (175°C).
Prepare the Baking Dish: Pour the melted butter into a 9x13 inch baking dish.
Make the Batter: In a large mixing bowl, whisk together the flour, 1 cup of sugar, baking powder, and salt. Add the milk and vanilla extract, whisking until the batter is smooth.
Pour the Batter: Pour the batter evenly over the melted butter in the baking dish. Do not stir.
Add the Filling: Spoon the lemon pie filling evenly over the batter. Do not stir.
Add the Topping: In a medium mixing bowl, combine 1/2 cup of sugar and the lemon zest. Sprinkle the sugar mixture evenly over the lemon pie filling and batter.
Bake: Bake in the preheated oven for 45 minutes, or until the top is golden brown and the cobbler is set.
Serve: Remove from the oven and let cool for a few minutes before serving. Enjoy warm with a scoop of vanilla ice cream if desired.