Preheat your oven to 350 degrees Fahrenheit. This is an essential step, as a preheated oven helps the cake rise properly from the moment it goes in. While the oven warms up, gather all your ingredients and get ready to mix!
Grease and flour a 9×13 baking dish. This prevents the cake from sticking and ensures that it comes out easily once baked. I find that using a bit of butter to grease the pan helps create a nice golden crust.
In a large bowl, whisk together the flour, sugar, and baking soda. Mix them thoroughly so that the baking soda is evenly distributed, which is crucial for a uniform rise.
Add the vanilla extract, crushed pineapple (including its juice), and eggs to the dry mixture. Stir gently until everything is combined, being careful not to overmix. The batter should be slightly lumpy, which is perfectly fine!
Pour the batter into the prepared baking dish, ensuring it’s evenly spread out. This helps the cake bake uniformly, so no part is overly dense or undercooked. Place it in the oven and bake for 25 to 30 minutes.
Check for doneness by inserting a toothpick in the center of the cake. It should come out clean or with just a few crumbs attached. If it needs more time, keep a close eye on it to prevent over-baking.
Once baked, let the cake cool completely in the pan on a wire rack. This is important as it allows the cake to set and makes it easier to frost later.
In a separate bowl, whisk together the remaining crushed pineapple and the vanilla instant pudding mix until well combined. This mixture will create a flavorful layer that complements the cake.
Gently fold in the Cool Whip until thoroughly combined. This mixture should be light and fluffy, perfect for spreading on top of the cake.
Once the cake is completely cool, spread the pineapple and whipped topping mixture over the top. Be sure to cover it evenly for a pretty finish!
Refrigerate the cake for at least 30 minutes before serving. This helps the flavors meld together and makes for a refreshing slice.