Preheat your oven to 350°F (175°C). Grease and lightly flour your baking pan, or line it with parchment paper for easier removal later.

Prepare the marble cake mix according to the instructions on the box. Usually, this means combining the mix with eggs, oil, and water as directed. Stir until smooth.

Pour about two-thirds of the cake batter into the prepared pan. Set the remaining batter aside for marbling.

In a small bowl, dissolve the strawberry-flavored Jell-O in 1 cup of boiling water. Allow it to cool for about 5 minutes so it thickens slightly but doesn’t set.

Mix half of the cooled strawberry mixture into the reserved cake batter. Swirl this strawberry batter into the pan using a knife or skewer to create a marble effect.

Bake for 35–40 minutes, or until a toothpick inserted into the center comes out clean. Once done, remove the cake from the oven and let it cool completely on a wire rack.

While the cake cools, prepare the vanilla pudding by whisking together the instant pudding mix and 2 cups of cold milk until it thickens. In a separate bowl, beat the whipped topping mix with vanilla extract according to package instructions. Fold the whipped topping into the pudding to make a light, creamy frosting.

Once the cake has cooled, spread the vanilla cream mixture evenly over the top. For extra flavor, drizzle a small amount of the leftover strawberry mixture over the frosting and gently swirl. Chill in the refrigerator for at least 1 hour before serving.