Moist buttermilk crumb, brown sugar base, and a topping made from crushed Heath bars. The toffee caramelizes in the oven into a golden and crunchy topping that makes this cake impossible to stop eating. Wonderful for breakfast, as a snack, or as dessert.
Preheat the oven to 350°F (175°C). Grease a 9x13 inch baking pan.
In a large mixing bowl, combine the butter, brown sugar, granulated sugar, and flour. Mix with a hand or standing mixer until well combined and there are no more lumps. Reserve ½ cup of this dry mixture and set it aside for the topping.
Add the egg, baking soda, vanilla, and buttermilk to the bowl. Mix with the hand or standing mixer until the batter is smooth. Mix until smooth but do not overmix. Scrape the sides and bottom of the bowl to make sure all the dry mixture is blended in.
Pour the batter into the prepared pan and spread evenly with a spatula.
Roughly crush the Heath bars in their wrappers using your fingers or a kitchen mallet. Keep the pieces chunky, not fine. Cut one end of each wrapper open and pour into a small bowl. Combine with the reserved ½ cup dry mixture and the chopped nuts (if using). Spread this topping evenly over the batter.
Bake for 30 minutes, or until a toothpick inserted into the center comes out clean. Let cool for 5 to 10 minutes before slicing and serving.
Notes
Suggested serving size is one square. The 9x13 dish can be cut into 12 equal pieces.
How to store:
Store in an airtight container at room temperature for up to 4 days.
Cover the pan tightly if storing in the baking dish.
Nutritional information provided is an estimate only, calculated using online calculators and do not include suggested or optional ingredients. Variations can occur due to ingredient freshness, brands, and measuring techniques.