Ingredients:
- For the brownies:
- 2 1/2 cups toasted walnuts
- 2/3 cup all-purpose flour
- 1/3 cup unsweetened cocoa powder (preferably Dutch process)
- 1/2 teaspoon salt
- 5 teaspoons instant espresso
- 6 ounces unsalted butter
- 5 ounces unsweetened chocolate
- 4 large eggs
- 2 cups granulated sugar
- 1 teaspoon vanilla extract
- 1/3 cup full-fat sour cream
- For the espresso ganache:
- 9 ounces bittersweet chocolate, broken into 3/4-inch pieces
- 3/4 cup plus 3 tablespoons heavy cream, divided
- 3/4 teaspoon instant espresso powder
- Sea salt, for garnish