01 -
Heat the oven to 325°F (165°C). Grease two 8-inch round cake pans, line the bottoms with parchment paper, and grease the parchment.
02 -
Whisk sugar, flour, baking soda, and salt in a large bowl. Bring the coffee just to a simmer, remove from the heat, and whisk in 1 cup of chocolate morsels until melted and smooth. Cool for 5 minutes.
03 -
In a second bowl, whisk oil, sour cream, eggs, and 1 1/2 teaspoons vanilla until smooth. Whisk in the chocolate-coffee mixture. Add this wet mixture to the dry ingredients in 3 additions, whisking until smooth after each addition. The batter will be thin.
04 -
Divide the batter between the pans. Bake for 33-35 minutes, until the centers spring back lightly and a toothpick comes out with a few moist crumbs. Cool in the pans for 10 minutes, then turn out onto racks and cool completely.
05 -
Bring cream, butter, sugar, water, and salt to a gentle simmer in a saucepan, stirring often. Remove from the heat, add the remaining 1 2/3 cups morsels, and let stand for 2 minutes. Whisk until smooth, then stir in 1/2 teaspoon vanilla.
06 -
Pour the frosting into a bowl and refrigerate, stirring every 20 minutes, until thick enough to spread, about 1 1/2 hours. It should look glossy and soft, not runny.
07 -
Place one cake layer on a plate and spread frosting over the top. Add the second layer, then frost the top and sides. Refrigerate to set, then bring to room temperature before slicing.