Heat oven to 350°F. Beat sugar and butter in a bowl until combined. Beat in eggs, then chocolate, then sour cream. Sift flour and baking soda in a bowl; add to chocolate mixture. Beat in coffee, vanilla and salt until combined. Coat a 9” x 13” pan with cooking spray; pour in batter.
Bake until a toothpick inserted in center comes out clean, 35 minutes.