- Preheat the oven to 400F then slice the butter and place it in a 9x13 inch baking dish and place in the oven while the oven preheats to melt the butter. - 5 tbsp butter 
- In a large bowl, mix the blueberries with the sugar and lemon zest. Stir to combine.  - 4 cup blueberries, 1/3 cup granulated sugar, 2 tsp lemon zest 
- In a separate bowl, whisk all-purpose flour, sugar, cornstarch, baking powder, and salt until combined. Add in the milk and vanilla extract and whisk until a batter forms. - 1 cup all-purpose flour, 3/4 cup granulated sugar, 1 tbsp  cornstarch, 2 tsp baking powder, 1/4 tsp salt, 3/4 cup milk, 1 tsp vanilla extract 
- Evenly distribute the blueberry mixture in the prepared pan once the butter is melted. Drizzle the batter over the blueberries and bake in the preheated oven for 25-30 minutes. You'll know it's ready when the fruit is bubbly at the edge and a toothpick inserted in the cobbler part comes out clean. 
- Allow it to cool down a little bit before serving it with some whipped cream, a drizzle of heavy cream, or vanilla ice cream.