Preheat your oven to 350 degrees F. This step is crucial as it ensures your cake bakes evenly and thoroughly.
In a medium-sized bowl, combine 1/2 cup melted butter with the cake mix and 1 egg. Stir well until everything is mixed together smoothly. Press the dough into a lightly greased 9x13 cake pan, creating a nice, even layer. Set this aside while you prepare the topping.
In the bowl of your stand mixer, beat 8 oz cream cheese until it’s nice and smooth. This should take about 2 to 3 minutes. Then slowly add in the melted butter and beat until well combined. The mixture should be creamy and luscious.
Add the remaining 2 eggs one at a time, mixing well after each addition. This helps to incorporate air into the cake, making it light and fluffy.
Next, add 1 tsp vanilla extract and 16 oz powdered sugar, whipping until everything is combined, and the mixture is smooth. Scrape down the sides to ensure no lumps remain.
Gently fold in 1/2 cup walnuts and 1/2 cup drained pineapple using a spatula. This will add a delightful crunch and burst of flavor to your cake.
Pour this cream cheese mixture over the crust you prepared earlier, spreading it evenly to ensure every bite is delicious.
Bake in the preheated oven for about 40 to 45 minutes. The center should still be slightly gooey when you take it out, so don’t overbake!
Once baked, remove it from the oven and let it cool completely before serving. Dust the top with powdered sugar for a beautiful finish and add a dollop of whip cream if desired. Enjoy your creation!