Fill a pot about half way with water and put on a medium/low stove.
While the water is heating up, cut the butter into cubes and coarsely chop the chocolate bar. Put both in a glass bowl and set the glass bowl over the pot with water. Stir the butter and chocolate until fully melted and shiny. Turn off stove and take glass bowl off of the pot. Set aside to cool.
Preheat oven to 350 degrees Fahrenheit.
Take your 8x8 baking pan and place parchment paper on the bottom and sides for easy brownie removal. Set aside.
Sift the flour, cocoa powder and salt together in a bowl so there are no clumps. Set aside.
In a large bowl, break in 3 eggs and add all of the granulated sugar. Using a hand mixer on high, mix the eggs and sugar. The mixture will become more pale and almost double in size. Mix for about 3-5 minutes or until the mixture leaves a trail off the beaters for two seconds.
Gently fold in the cooled chocolate bar/butter mixture with a spatula until fully incorporated. Be sure to be gentle when folding in so you don't knock the air out of the mixture. I usually do a figure 8 motion.
After the chocolate mixture is incorporated, fold in the flour/cocoa powder mixture till completely mixed together, still being gentle. The mixture should now look fudgy.
Stir in the chocolate chips.
Mix the 1 tsp of instant coffee with the 1 tsp of warm water. Pour mixture into batter.
Pour in 1/2 tsp of vanilla extract. Fold the coffee and and vanilla into the batter.
Pour the batter into your parchment lined 8x8 baking pan. Making sure the batter is spread out to all the corners and is an even height.
Bake in your preheated oven for about 35-40 minutes (turning halfway through). I usually check the batter at around 30-35 minutes. If the center still jiggles, it needs more time. I stick a tooth pick in the middle for a final check. If it comes out mostly clean, you're good to go!
Let the brownies sit in the pan until it is completely cooled. Cut and enjoy!