Cut pound cake vertically into 10 equal-size slices. Drizzle coffee over each slice; set aside.

In a large bowl, combine whipped topping and 1/4 cup cocoa, mixing until blended. Place 5 cake slices on a flat surface. Evenly spread a thick layer of whipped topping mixture over each slice. Top each with a second cake slice, sandwich-style. Transfer to individual dessert plates. Spread each cake "sandwich" with whipped topping mixture. Cut "sandwiches" diagonally in half. Sprinkle with remaining cocoa; serve immediately.