- Preheat oven at 325 degrees F. Prepare a 9" X 9" baking pan with aluminum foil, allowing some foil to hang over the edges. Spray foil with cooking spray.
- Bring stout to a boil and reduce to simmer. Cook for 10 minutes, or until reduced to 1/4 cup. Set aside to cool.
- Using a double broiler melt chocolate chips and butter over high heat, stirring occasionally until melted.
- Add sugar, vanilla, salt and stout and mix well with a wooden spoon. Mix in eggs one at a time.
- Fold flour into mixture then pour into baking pan. Bake for 40 minutes - 45 minutes, or until toothpick comes out clean. Using foil or parchment overhang, lift brownies from pan. Allow to cool for 2 hours or overnight to firm up then cut into squares. Dust with powdered sugar if desired.