Step 1

Preheat the oven to 350 degrees F.

Step 2

Coat a 9x13-inch baking dish with nonstick cooking spray.

Step 3

Prepare the lemon cake mix according to package directions.

Step 4

Evenly pour the lemon cake batter into the prepared baking dish.

Step 5

In a large bowl, add the instant pudding, the sugar, the milk, and the water and briskly whisk until the pudding mixture begins to thicken, about 2 minutes.

Step 6

Immediately, evenly spoon the pudding mixture over the lemon cake batter. Do not mix together. The pudding mixture will somewhat sink into the lemon cake batter.

Step 7

Place the baking dish on a large baking sheet to prevent spillage.

Step 8

Bake the cake until a toothpick inserted into the center comes out with pudding only, no cake batter, about 55-60 minutes. The center of the cake will be somewhat loose because of the pudding.

Step 9

Transfer the baked cake to a wire rack to cool, about 20 minutes.

Step 10

Dust the cake with the confectioners' sugar, slice, and serve.