Fudgy Crinkle Top Brownies

Preheat your oven to 350℉.
In a medium-sized mixing bowl, melt together the butter and dark chocolate.
If you melt using the microwave, stop and stir every 20 seconds to prevent the chocolate from seizing.
Stir in the cocoa powder and espresso powder while the mixture is still hot.
Set aside.
In another mixing bowl, whisk together the eggs, both sugars, and vanilla until pale yellow and frothy. The sugar should be fully dissolved.
To test this: rub a bit of the mixture between your fingers. If you still feel lots of sugar granules, keep whisking.
Once the melted butter/chocolate has cooled, fold in the whisked egg/sugar mixture.
Use a silicone spatula to gently combine the flour and salt into the bowl.
If you have any mix-ins like nuts or chocolate chips, add them at this step.
Spray an 8x8 brownie pan with nonstick cooking spray, then pour the batter into the pan. Smooth the top into an even layer.
Bake for 35 - 40 minutes, until the tops are shiny and the middle of the brownie no longer wobbles.
Let the brownies cool completely, then cut and serve. For the cleanest cuts, use a plastic knife and wipe with a towel after each cut. Enjoy!