Method

1. Gather all ingredients. Preheat the oven to 350 degrees F (175 degrees C). Grease a 9x13-inch baking pan with cooking spray and line with parchment paper, if desired.

2. Beat cake mix, water, eggs, and oil in a large bowl with an electric mixer at low speed until moistened, about 30 seconds. Beat at medium speed until no streaks of flour remain, about 2 minutes. Rinse beaters clean.

3. Pour batter into the prepared baking pan.

4. Bake in the the preheated oven until a toothpick inserted into the center of the cake comes out clean, 21 to 25 minutes.

5. Five minutes before cake is done, whisk together pudding mix and milk in a saucepan; heat over medium, whisking constantly, until mixture starts to thicken, about 4 minutes. Remove from heat. Add salt and 1/2 cup of the Irish cream and whisk vigorously until smooth.

6. Poke holes immediately into the warm cake with the round handle of a wooden spoon. (Holes should be at 1-inch intervals and extend down to the bottom of the baking dish.)

7. Immediately pour pudding mixture evenly over the warm cake, making sure to fill all the holes. Let cool in pan on a wire rack until room temperature, about 30 minutes. Cover and refrigerate for at least 2 hours or up to 12 hours.

8. Combine heavy cream, 6 tablespoons caramel topping, and remaining 3 tablespoons Irish cream in a large bowl. Beat on medium-high speed until stiff peaks form, about 5 minutes. Refrigerate until needed.

9. Spread whipped cream evenly over cooled cake.

10. Drizzle with remaining 2 tablespoons salted caramel topping. Sprinkle with flaky sea salt, if desired.