01 -
Preheat oven to 350°F. Spray a 9x5-inch loaf pan with nonstick cooking spray and line with parchment paper, leaving 2-inch overhang on two sides.
02 -
In a large bowl, whisk sugar, eggs, stout beer, vegetable oil, vanilla extract, and instant coffee granules until smooth, about 2 minutes.
03 -
Sift flour, cocoa powder, baking powder, baking soda, and salt over the wet mixture. Gently fold until a few dry streaks remain.
04 -
Pour boiling water into batter and whisk until smooth; batter will be thin. Scrape into prepared pan.
05 -
Bake in preheated oven until a toothpick inserted comes out with moist crumbs but no wet batter, about 55 minutes. Remove from oven and cool on wire rack for 1 hour.
06 -
Whisk together powdered sugar, Baileys or heavy cream, and salt until smooth and pourable but thick enough to coat the cake. Adjust consistency with additional powdered sugar or Baileys as needed.
07 -
Lift cooled cake from pan using parchment overhang. Pour glaze over cake, spreading evenly. Optionally sprinkle with shaved dark chocolate. Let set 10 to 15 minutes before slicing and serving.