Preheat the oven to 350°F. Grease a 9×13-inch cake pan and line two baking sheets with parchment or wax paper.

Combine the cake mix, water, vegetable oil, and eggs in a large mixing bowl. Pour the batter into the prepared cake pan.

Bake for 26 to 31 minutes or until a toothpick inserted into the center comes out clean. Let the cake cool completely.

Break the cooled cake into fine crumbs. Add the softened cream cheese and peanut butter, then mix until evenly combined. The mixture should hold together when pressed.

Refrigerate the cake balls for 30 to 60 minutes.

Place one package of melting wafers in a small microwave-safe bowl. Microwave according to the package directions, stirring every 20 to 30 seconds, until smooth.

Dip each chilled cake ball into the melted coating using a fork or truffle dipper. Let the excess coating drip back into the bowl, then place the truffle on the lined baking sheet. Add candy eyes or sprinkles before the coating sets. Melt the second package of wafers as needed.

Refrigerate the truffles until the coating is firm.

For an optional colored drizzle, melt additional vanilla wafers and tint them with oil-based candy color. Drizzle over the coated truffles and let the decoration set before serving.