Preheat oven to 300F. Line a 9×9-inch pan with foil, spray with cooking spray; set aside.
In a large microwave-safe bowl, add the butter and heat for 1 minute on high power to melt. It’s okay if it hasn’t melted after 1 minute.
Add 2 cups chocolate chips, one heaping half-cup peanut butter, coffee (doesn’t make the brownies taste like coffee and serves to enhance and bring out the chocolate flavor), and heat for 1 minute on high power to melt.
Whisk mixture until smooth. If necessary, heat in 10-second bursts until mixture can be whisked smooth.
Add the eggs, sugar, vanilla, and whisk until smooth.
Add the cocoa, optional espresso granules, and whisk until smooth.
Turn batter out into prepared pan, smoothing the top lightly with a spatula.
Bake for about 35 minutes or until edges are set, and the top and center have just set and are not jiggly. A toothpick inserted in the center should come out with a few moist crumbs, but no batter. Place pan on a wire rack and allow brownies to cool completely, at least 2 hours, before adding the drizzles. If you add the drizzles to warm brownies, they’ll melt together and while it tastes the same, cosmetically it isn’t what’s shown.
After brownies have cooled, add 1/2 cup chocolate chips to a small microwave-safe bowl and heat on high power to melt, about 1 minute. Stir until smooth and drizzle over brownies using a spoon or squirt bottle; set aside.
Add 1/3 cup peanut butter to a small microwave-safe bowl and heat on high power to melt, about 45 seconds. Drizzle over brownies using a spoon or squirt bottle.
I recommend chilling the brownies before serving because they’re rich, bold, and taste better when chilled. Cover pan with a sheet of foil to prevent fridge smells and chill brownies for at least 4 hours, or overnight, before serving. Brownies will keep airtight in the refrigerator for up to 10 days.