Ingredients:
- 1/2 cup (1 stick) unsalted butter, plus more for pan
- 1 cup sifted all-purpose flour, plus more for pan
- 5 ounces unsweetened chocolate
- 3 large eggs
- 1 1/2 cups sugar
- 2 teaspoons pure vanilla extract
- 1/2 teaspoon salt
- Blackberry Ice Cream, for serving