Prepare four different bowls with the ingredients listed below. You'll work with bowls A through D in-order. Bowl B should be your largest bowl, since it will end up holding all of the ingredients.
Preheat your oven to 350 degrees.Prepare your baking pan: I use a 9" x 13" pan so that my brownies are the thickness I require for my version of "perfection." If you like thinner brownies, use a larger pan so that the batter can be spread thin.Take a pat of butter and use your fingers to spread it over every inch of the inside of the pan. Do yourself a favor and dust with unsweetened cocoa powder, like I do. Dusting the pan with flour tends to leave a bitter aftertaste on the outside of the brownie crust. I recommend dusting all baked chocolate desserts, with chocolate instead of flour.Now, let's prepare the first ingredients we'll work with, to make a chocolate sauce.
Create a double-broiler to melt the ingredients together. Place 1-2 inches of water into a saucepan. Place on medium-low heat. Once you see tiny bubbles forming in the water, it's time to place the glass bowl (A) onto the top.The trick to melting/tempering chocolate is to be sure additional moisture is not added, while it's over a heat source. Therefore, I recommend always using a baking spatula and not a wood spoon (since wood retains moisture) to mix while melting.Use the spatula to coat the chocolate with the butter. After about 4 minutes, the water will increase in heat and start to boil. At that point, bring the heat down to low. Continue turning the chocolate. It will take approximately 10 minutes total, to melt the chocolate to become completely smooth.
Remove the bowl from heat, and set this aside to cool. Before mixing in the rest of the ingredients, the chocolate sauce should cool for 10 minutes. Since the rest of this recipe will fly-by, I recommend setting a timer so you know when to move onto the next steps.
Again, this should be the largest bowl, since all of the contents will end up here.Place the sugar, eggs, pure vanilla extract (and if you're using it, the fresh-brewed espresso). Use a spatula to break it down and mix it together. There's no need to whisk or beat.Next, pour the cooled, melted chocolate of BOWL A, into the egg and sugar mixture of BOWL B.Mix together. You'll notice how the texture changes, into a thickened mixture, that gives resistance against the spatula. Once the chocolate is incorporated, add the dry ingredients from BOWL C. It won't take long to combine. Last, you'll add the ingredients from BOWL D. Mix just enough, until there are no traces of white from the flour. Pour the batter into the prepared pan.
Place the pan at the center rack of your oven. For this size pan, the brownies are done after 35 minutes. Take out at this time. Don't over cook or allow for dark-browning/burning at the edge or top. A couple specs of dark at the top are perfectly fine. Allow to cool. It will take time for the rise in the center to flatten. Once it's flat, you can cut and serve, or put the pan in the refrigerator to cut and serve when you are ready. I like to cut them into portions, individually wrap them and then place them in an air-tight container, so that they do not stale and I can enjoy them at least two days later, if there are any left.