A note before you begin: Be prepared to make the topping while the strawberries are baking since the topping must be added to the strawberries when they are hot. If you are not going to make the topping right away, just set the strawberries aside.)
Preheat the oven to 375°F and grease a 9x13-inch baking pan with butter. I like to use whatever butter is left on the wrapper that I'm using in the strawberry mixture.
4 tablespoons salted butter
Pre the 6 cups sliced strawberries by slicing into rounds and placing in a large bowl, set aside.
In a large bowl, whisk together the 1 cup granulated sugar, ¼ cup light brown sugar, and 1 teaspoon lemon zest to infuse the sugars with lemon flavor.
1 cup granulated sugar, ¼ cup light brown sugar, ¼ cup all-purpose flour, ¼ teaspoon salt, 1 tablespoon lemon juice, 1 teaspoon lemon zest, 6 cups sliced strawberries, ½ teaspoon vanilla extract
Add in ¼ cup all-purpose flour and ¼ teaspoon salt and whisk together.
Stir in 2 ounces vanilla simple syrup, 1 tablespoon lemon juice, and ½ teaspoon vanilla extract until a thick paste forms. Then add in the prepared 6 cups sliced strawberries from step 3 and the 4 tablespoons salted butter and toss until evenly coated, breaking the soft butter up with the rubber spatula as your stir.
Pour this mixture into the prepared baking dish and bake for 15 minutes.
While the strawberries are baking, prepare the topping by adding 2 cups all-purpose flour, 1 cup granulated sugar, and 2 teaspoons baking powder to a food processor and pulse together.
½ cup buttermilk
Add the sliced ¾ cup salted butter and pulse just until the mixture is crumbly/sandy looking (do not overmix).
¾ cup salted butter
Pour in ½ cup buttermilk and 1 teaspoon vanilla extract and pulse just until the crumbs are moistened. Drop this mixture in clumps onto the hot strawberries as soon as they come out of the oven. If you allow the strawberries to cool at all, the topping will not bake properly. It is okay if there is some space between the clumps of topping.
1 teaspoon vanilla extract
Bake for 32 to 35 minutes until the top is golden brown.
Serve right out of the oven for a saucier cobbler, or let sit for an hour to thicken up. This cobbler can be enjoyed warm or at room temperature.