For the cake:

1. Preheat your oven to 350°F (175°C) and grease a 9×13-inch baking dish.

2. In a saucepan, bring the water, salt, and butter to a boil. Once the butter is melted, remove from heat.

3. Stir in the flour all at once, mixing until a smooth dough forms. Return the pan to heat and cook the dough for 1 minute, stirring constantly.

4. Remove from heat, let cool for a few minutes, and then add eggs one at a time, mixing well after each addition.

5. Spread the dough evenly into the prepared baking dish and bake for 30-35 minutes until golden brown and puffed. Let the cake cool completely.

For the filling:

1. In a medium bowl, combine the instant pudding mix with 3 1/2 cups milk. Whisk until thickened, about 2 minutes.

2. In another bowl, beat the softened cream cheese until smooth.

3. Gradually fold the pudding mixture into the cream cheese until smooth and creamy.

4. Once the cake has cooled, spread the cream cheese pudding mixture evenly on top.

5. Refrigerate for at least 2 hours to set.

To serve:

1. After chilling, cut into squares and serve. Optional: top with whipped cream or powdered sugar for extra sweetness.