Preheat your oven to 350°F (175°C) and line a rimmed baking sheet with parchment paper.

In a large mixing bowl, combine the chocolate cake mix, eggs, and water. Blend until smooth, about 2-3 minutes.

Pour the batter into the lined baking sheet and spread it evenly. Bake for 12-15 minutes or until a toothpick comes out clean.

Let the cake cool in the pan for about 5 minutes, then transfer it to a wire rack to cool completely.

In a medium bowl, mix the creamy peanut butter, heavy cream, and powdered sugar until smooth.

Spread the peanut butter filling evenly over the cooled cake, leaving a small border around the edges, and sprinkle with chopped peanut butter cups. Roll the cake tightly from one end using the parchment paper.

Wrap the rolled cake in plastic wrap and refrigerate for at least 1 hour to set.

Slice the cake roll into pieces and serve with additional peanut butter cups if desired.