Step 1: Prep: Preheat oven to 350°F (175°C). Line an 8x8-inch baking pan with parchment paper or lightly grease it.

Step 2: Make the Brownie Batter: In a saucepan, melt butter and chocolate chips together over low heat, stirring until smooth. Remove from heat and whisk in granulated sugar and brown sugar. Stir in the eggs and vanilla extract until fully combined. Sift in flour, cocoa powder, and salt, then gently fold until just combined (don’t overmix).

Step 3: Bake the Brownies: Spread the batter evenly into the prepared pan. Bake for 25 minutes or until a toothpick comes out with moist crumbs (not wet batter).

Step 4: Add Marshmallow Topping: Remove the brownies from the oven and immediately scatter mini marshmallows (and chocolate chips, if using) evenly over the top. Return to the oven for 3–5 minutes until marshmallows are puffed and slightly golden.

Step 5: Finish u0026 Cool: Remove from oven and dust with hot cocoa mix for an authentic touch. Let brownies cool in the pan for about 20 minutes before cutting into squares.