INGREDIENTS
•
For the cake:
•
5 ounces (145 grams) good-quality dark or extra dark chocolate (semisweet or bittersweet), chopped (I used Callebaut Dark Callets)
•
2 1/4 sticks (9 ounces/260 grams) unsalted butter, softened
•
2 3/4 cups (11 ounces/315 grams) cake flour (not self-rising), sifted *see notes
•
1/4 cup (24 grams) unsweetened cocoa powder (not Dutch-process, such as Ghirardelli Chocolate Baking Cocoa)
•
2 teaspoons (12 grams) baking soda
•
1 teaspoon (5 grams) baking powder
•
1/2 teaspoon (4 grams) salt
•
4 large eggs, at room temperature 30 minutes
•
1 cup (7 ounces/200 grams) granulated sugar
•
1 cup (7.5 ounces/220 grams) packed light brown sugar
•
1 1/2 teaspoons (7.5 mL) pure vanilla extract (I use Nielsen-Massey Vanilla)
•
2 cups (475 mL) sour cream
•
FROSTING
•
1 cup (7 ounces/200 grams) granulated sugar
•
6 tablespoons (47 grams) all-purpose flour
•
6 tablespoons (36 grams) unsweetened cocoa powder (natural, not Dutch-process, such as such as Ghirardelli Chocolate Baking Cocoa) *see notes
•
1 1/2 cups (360 mL) whole milk
•
4 ounces (115 grams) good-quality dark or extra dark (semisweet or bittersweet) chocolate, finely chopped (I used Callebaut Dark Callets)
•
1 tablespoon (15 mL) pure vanilla extract (I used Nielsen-Massey Vanilla)
•
6 sticks (1.5 pound/680 grams/3 cups) unsalted butter, at room temperature