Preheat oven to 350 degrees. Line a 9″ x 9″ pan with parchment paper, and spray with cooking spray.

In microwave, melt semi-sweet chocolate, espresso powder, and butter for 15 second intervals, stirring each time until completely melted. Mix in Blackout Stout and set aside. In a separate large bowl, add sugars, vanilla extract, salt, and eggs. Beat with electric hand mixer until light and fluffy, with a thick consistency. Combine chocolate/butter and egg mixtures and blend with mixer until smooth. Sift in flour and cocoa powder, using rubber spatula to gently fold until just combined. Do not overmix.

Pour batter into prepared pan. Add optional Blackout Stout reduction (recipe below). Smooth out top and bake for 12 minutes. Remove pan from oven and gently drop on a flat surface 1-2 times until brownies deflate slightly and the smooth, shiny top cracks. Sprinkle with flaky sea salt. Return pan to oven and continue baking for an additional 10 minutes. 

Bake until a toothpick inserted into center comes out fudgy but edges look cooked through. Cool brownies in pan, then cut and serve.

Blackout Stout Reduction (Optional):

Pour Blackout Stout into a small saucepan. On stovetop, bring beer to a boil, then reduce heat to a simmer. Stir occasionally until beer has reduced to ¼ cup, about 20-25 minutes. Once beer has reduced sufficiently, add sugar and stir to dissolve. 

After pouring the brownie batter into the prepared pan, drizzle the reduction evenly on top, and swirl with a toothpick. Bake as directed above. May require an additional 5 minutes of baking time.