Bake the Cake: Preheat the oven to 350°F (175°C). Grease a 9x13-inch baking dish. In a large mixing bowl, prepare the cake batter according to the instructions on the box by combining the cake mix, water, vegetable oil, and eggs. Transfer the batter into the prepared baking dish and bake for 25 to 30 minutes, or until a toothpick inserted in the center emerges clean. Allow the cake to cool slightly.

Prepare the Poke Mixture: In a small bowl, dissolve the raspberry-flavored gelatin in 1 cup of boiling water, stirring until completely dissolved. Incorporate 1 cup of cold water and mix thoroughly until well combined.

Poke the Cake: Using the handle of a wooden spoon or a straw, poke holes evenly across the top of the cake (about 1 inch apart). Pour the raspberry gelatin mixture over the cake, allowing it to soak into the holes. Cover and refrigerate for at least 2 hours, or until completely cooled.

Make the Topping: In a medium bowl, use an electric mixer to beat the softened cream cheese until it reaches a smooth consistency. Gradually add the powdered sugar and vanilla extract, mixing until thoroughly blended. Carefully fold in the whipped topping until the mixture is smooth and creamy.

Assemble the Cake: Spread the cream cheese and whipped topping mixture evenly over the cooled cake. Smooth it out with a spatula.

Garnish and Serve: Garnish with fresh raspberries on top, if desired. Cut into slices and serve chilled to enjoy the optimal flavor and texture.