Ingredients
Equipment
Method
- Preheat your oven to 350°F (175°C). Line a 9×13-inch baking pan with parchment paper, leaving some overhang for easy removal. Lightly grease the parchment paper with cooking spray or butter.
- In a large mixing bowl, whisk together the granulated sugar, eggs, and egg yolk until well combined and slightly pale. Add melted butter, vanilla extract, and oil, mixing until smooth and incorporated.
- In another bowl, sift together the flour, cocoa powder, cornstarch, and salt. This helps remove lumps and ensures a smooth brownie texture.
- Gradually fold the dry ingredients into the wet mixture using a spatula. Mix just until combined to keep brownies soft. Fold in the chocolate chips.
- Pour half of the brownie batter into the prepared pan. Drop spoonfuls of marshmallow creme over the batter, then top with the remaining batter. Use a knife to create gentle swirl patterns through the layers.
- Bake for 28–32 minutes, or until a toothpick inserted into the brownie (not the marshmallow) comes out with a few moist crumbs. The marshmallow will puff and lightly brown.
- Let the brownies cool completely in the pan before cutting. This helps them set and makes cleaner slices. Enjoy your gooey, fudgy marshmallow brownies!
Notes
For extra indulgence, sprinkle mini marshmallows or drizzle melted chocolate on top after baking. You can substitute canola oil with coconut oil for a subtle flavor change. Store in an airtight container for up to 4 days or refrigerate for a fudgier texture.