Preheat your oven to 350°F (175°C).
Pour melted butter into a 9×13-inch baking dish.
In a large bowl, whisk together granulated sugar, brown sugar, flour, baking powder, salt, and cinnamon.
Add vanilla extract and stir to combine.
Sprinkle the dry mixture evenly over the melted butter in the dish. Do not stir.
Slowly pour the hot water over the top. Do not stir.
Bake for 40-45 minutes, or until the top is golden brown and cobbler is set.
Allow to cool slightly before serving.