Ingredients
Method
- Preheat the oven to 325°F and prepare a 9x9-inch pan with nonstick spray and parchment paper, leaving overhang on two sides for easy removal.
- Sift together the flour, cocoa powder, and cornstarch in a mixing bowl, then stir in the salt until evenly combined.
- Whisk the sugar, eggs, and egg yolk with an electric mixer on high speed for about 5 minutes until thick and pale.
- Blend the cooled melted butter, oil, and vanilla into the egg mixture until smooth and fully incorporated.
- Gently mix the dry ingredients into the wet mixture just until no dry streaks remain.
- Fold the chocolate chips through the batter using a spatula until evenly distributed.
- Transfer the batter to the prepared pan and spread it into an even layer.
- Warm the marshmallow creme briefly until spreadable, then spoon small dollops over the brownie batter and lightly swirl with a knife.
- Bake for 45 to 55 minutes, or until a toothpick inserted near the center comes out with a few moist crumbs attached.
- Place the pan on a wire rack and allow the brownies to cool completely before slicing into squares.
Nutrition
Notes
These marshmallow swirl brownies are the kind of treat that disappears from the pan before they've even fully cooled — impossibly fudgy, deeply chocolatey, with that gorgeous toasted marshmallow top that makes every square look like it came straight from a bakery case. Let them cool completely for clean cuts and the most satisfying bite.