Preheat oven to 350°F. Spray a 9x13-inch pan with baking spray.
Make the cake mix according to package instructions with eggs, butter, and water. Add the crushed pineapple to the batter and stir to combine. Pour into the prepared pan.
1 yellow cake mix, 1 (20-ounce) can crushed pineapple, 1/2 cup salted butter, 3 large eggs, 1 cup water
Bake 25-28 minutes until done. Cool, then poke 20 holes with the end of a wooden spoon.
In a large bowl, whisk the vanilla pudding mix with 1 cup cold whole milk and 1/2 cup reserved pineapple juice until it starts to thicken slightly, about 1-2 minutes. Pour over the cake making sure to fill the holes with the pudding. Evenly spread with a spatula to cover the top of the cake.
1 (3.4-ounce) box instant vanilla pudding, 1 cup whole milk, 1/2 cup pineapple juice
Beat the heavy cream and powdered sugar with a stand mixer fitted with the whisk attachment or using an electric hand mixer until stiff peaks form. Fold in the drained 8-ounce can of crushed pineapple, then spread on top of the pudding layer. Refrigerate for 2 hours or overnight.
1 1/2 cups heavy cream, 1/3 cup powdered sugar, 1 (8-ounce) can crushed pineapple
Garnish with pineapple tidbits or chunks before serving.
1 (8-ounce) can pineapple tidbits or chunks