Preheat your oven to 350°F (175°C). Line your 8x8-inch baking pan with parchment paper or lightly grease it to make cleanup easier later on!

Melt the unsalted butter. I recommend using a microwave for convenience. Once melted, set it aside to cool slightly before moving on to the next step.

In a large bowl, mix together the granulated sugar and brown sugar. Pour in your melted butter and stir everything together until it’s nice and smooth.

Next, crack the eggs into the bowl and add the vanilla extract.

Sift the unsweetened cocoa powder into the bowl and add the all-purpose flour and salt. Stir everything together until it’s just combined. Don’t overmix. 

At this point, pour the brownie batter into the pan you've already prepared. Pop it into your preheated oven and bake for about 25 minutes.

After baking, take them out of the oven and immediately sprinkle the mini marshmallows and chopped pecans over the top. The brownies will stay hot enough to melt and cause the marshmallows to puff up.

melt the chocolate chips with 1 tablespoon of butter in the microwave. And pour it over the brownies.

Let the brownies cool in the pan for 10 minutes. Enjoy!