Joy the Baker's Strawberry Blueberry Cobbler

Place a rack in the upper third of your oven and preheat to 375°F (190°C). Lightly slick a 9-by 13-inch (23-by 33-cm) baking dish with softened or melted butter.
In a small bowl, stir together brown sugar, cornstarch, ginger, and salt until evenly combined.
Place the blueberries and sliced strawberries in the prepared baking dish. Add the sugar mixture and toss gently until evenly coated. Let the strawberries and blueberries macerate in the sugar while you prepare the topping. They’ll begin to release juice and that’s a good thing.

In a small saucepan over medium-low heat, cook the butter just until the milk solids toast and brown and the butter is very fragrant, 5 to 8 minutes. [Editor’s note: You are going to want to watch the butter closely as it can burn very quickly.] Pour the browned butter into a medium bowl to cool slightly.
Add the sugar, vanilla, flour, baking powder, and salt to the bowl with butter. Stir in the beaten egg yolk and use a fork or your fingers to work the ingredients into a shaggy dough.
Use your hands to shape the dough into rough coins about 3 inches (8 cm) in diameter. Layer atop the prepared strawberries and blueberries, covering the fruit as much as possible—though it’s ok if bits of fruit peek through.
In a small bowl whisk together egg white and a splash of milk. Lightly brush the cobbler top and sprinkle generously with turbinado sugar, if using.
Bake until the fruit is bubbling and the top is lightly golden, 25 to 30 minutes. Rotate the dish in the oven halfway through baking to evenly brown.
Remove from the oven and allow to rest for 15 minutes to cool just slightly before scooping and serving with vanilla ice cream or whipped cream. Cobbler is delicious at room temperature or cold from the fridge. There’s no wrong way to enjoy it! Cobbler is best enjoyed on the day it is made but will last, covered in the refrigerator, for up to 3 days.