Make the Cake:
Preheat oven to 350°F (175°C). Lightly grease a 9×13-inch baking pan.
In a large mixing bowl, whisk together sugar, flour, cocoa, baking soda, salt, and espresso powder.
Add cold water, oil, vinegar, and vanilla extract. Stir until smooth and well combined.
Pour the batter into the prepared pan and bake for 35–40 minutes, or until a toothpick inserted in the center comes out clean.
Let the cake cool for 10 minutes, then use the handle of a wooden spoon to poke holes all over the cake.

Make the Ganache:
Place the peanut butter and chopped chocolate in a heat-safe bowl.
Heat the cream in a small saucepan over medium heat until steaming but not boiling.
Pour hot cream over the peanut butter and chocolate. Let sit for 1–2 minutes, then whisk until smooth.
Pour the ganache over the warm cake, spreading it evenly and allowing it to seep into the holes. Let cool completely.

Make the Topping:
In a chilled mixing bowl, whip the cold cream with vanilla extract until soft peaks form.
Add confectioners’ sugar and peanut butter, and continue to beat until stiff peaks form.
Spread the topping evenly over the cooled cake.