In my family, my mother was known as the baker. Growing up, I remember her spending hours making wedding cakes, themed birthday cakes, and candies. Much of it I don’t recall as I was fairly young, but I do remember certain baked goods and candies that made regular appearances or were requested fairly often. One of those frequent requests just happened to be Sunken Treasure Cake.
It’s a devil’s food cake with crushed up Heath bars and a simple vanilla glaze on top. While baking, the candy pieces sink to the bottom of the cake, causing the chocolate coating to melt and moisten the cake and the toffee to change texture. Instead of the normal crunch a Heath bar has, the toffee slightly softens from the melted chocolate so that the outside is gooey but the middle of the larger chunks is still a little crunchy.
The recipe is super easy and I’ve not met a person yet who has not raved about this cake. I always prefer to use from-scratch recipes, but since this was being prepped for a party, I didn’t want to risk it not turning out. In fact, I decided to make this into cupcakes thinking that would be easier for the party guests. However, the candy didn’t sink and I was left pushing the candy pieces down into the batter half way through baking. They looked similar to the cake, with all those nooks and crannies showing where the “treasure” was, but the toffee didn’t seem to soften at all. With the leftover batter, I decided to try filling the cups half way, then sprinkling on the Heath pieces before filling the rest of the cup but it was still a no-go. So, I had the poor husband run out at 9:30 pm and pick me up another mix. Sometimes you just don’t mess with a good thing! Of course, by morning, the cupcakes had sat long enough that they seemed a bit better, but guests said the cake still tasted much better. My guess was that the candy didn’t spread out and melt enough. Either way, both the cupcakes and cake were near gone by party’s end!
Oh, and don’t let me forget the most important thing I’ve learned about this cake: while cutting your piece, you’ll feel the chunks of toffee – cut around them so that you get the whole chunk of toffee! I promise the person getting the piece next to yours will never know!
Sunken Treasure Cake with Vanilla Glaze
Makes a 13×9-inch cake
1 Devil’s Food Boxed Mix or your favorite from-scratch recipe
6 Heath bars or half a bag of fun-size/miniature Heath bars
2-3 cups confectioners sugar
2-3 tablespoons milk
1/2 teaspoon vanilla extract
To make the cake:
1. Preheat the oven to 350-degrees F (or whatever your recipe/box calls for.)
2. Place the Heath bars in a baggie and pound them. There should be a good mix of smaller and larger chunks – don’t pound them to dust!
3. Prepare the cake batter as noted and pour into a greased or nonstick 13×9-inch cake pan.
4. Sprinkle the crushed Heath bars evenly over the cake batter.
5. Bake as noted until a tooth pick comes out clean. Let cake cool completely in the pan on a wire rack.
To make the glaze:
1. Combine confectioners sugar and milk in a bowl and whisk until smooth. Add the vanilla extract. (Note: Glaze should have the consistency of corn syrup: if too thin, add a couple additional tablespoons of confectioners sugar; if too thick, add a small amount of milk.)
2. Using a spoon, drizzle over the completely cooled cake. Let glaze harden and serve.
Note: I’ve learned that if you need to store this, an airtight container will cause the glaze to liquefy due to all the moisture, even in the fridge. So your best bet is to eat it all (or leave a small opening in your container)!