Step 1: Preparing the Sweet Potato Puree
Preheat your oven to 375°F (190°C).
Wash and pierce the sweet potatoes with a fork. Place them on a baking sheet and roast for about 45 minutes or until they are fork-tender.
Let them cool slightly, then peel and mash until smooth. Set aside.
Step 2: Making the Brownie Batter
Reduce oven temperature to 350°F (175°C) and grease a 9x13-inch baking dish.
In a large mixing bowl, whisk together melted butter, granulated sugar, and brown sugar.
Add eggs one at a time, mixing well after each addition. Stir in vanilla extract.
Sift in cocoa powder, flour, salt, and baking powder. Gently fold the ingredients until just combined—don’t overmix!
Pour the brownie batter into the prepared baking dish and spread it evenly.
Step 3: Mixing the Sweet Potato Pie Layer
In a separate bowl, whisk together mashed sweet potatoes, brown sugar, eggs, heavy cream, vanilla extract, cinnamon, and nutmeg.
Mix until smooth and well combined.
Step 4: Layering and Baking
Gently pour the sweet potato mixture over the brownie batter, spreading it evenly with a spatula.
If you want a marbled effect, swirl the layers slightly using a knife or toothpick.
Bake for 35-40 minutes, or until a toothpick inserted in the center comes out with just a few moist crumbs.
Step 5: Cooling and Cutting
Let the brownies cool completely before slicing—this ensures they set properly and hold their shape.
Once cooled, slice into squares and enjoy!