'The Bear' Chocolate Cake

Baking spray with flour

2 1/2 cups all-purpose flour (about 10 5/8 ounces)

1 1/4 cups unsweetened Dutch-process cocoa powder (such as Valrhona) (about 4 3/8 ounces)

2 teaspoons baking soda

1 1/2 teaspoons baking powder

2 1/2 teaspoons kosher salt

5 large eggs, at room temperature 

3 cups granulated sugar

1 1/4 cups brewed coffee, at room temperature

3/4 cup unsalted butter (6 ounces), melted

1 1/2 cups crème fraîche (about 12 ounces), at room temperature 

Icing

6 cups powdered sugar (about 24 ounces)

1 1/2 cups unsweetened Dutch-process cocoa powder (such as Valrhona) (about 4 7/8 ounces)

2 1/4 cups unsalted butter (18 ounces), softened

1/2 cup heavy cream

2 teaspoons vanilla extract

Directions

Make the chocolate mousse

Bring 1 inch of water to a simmer in a small saucepan over medium-low. Place a medium-size heatproof bowl over pan; add chopped chocolate and butter. (Make sure bottom of bowl does not touch water.) Cook, stirring occasionally and adjusting heat as needed to maintain a simmer, until mixture is smooth, 3 to 5 minutes. Remove chocolate mixture from heat; let cool, uncovered, at room temperature until just warm to the touch, about 10 minutes. Reduce heat to low and keep water in the saucepan at a bare simmer.