Prepare a 9 x 13 dish with non stick spray or line with aluminum foil.
In a medium bowl, combine flour, salt and cocoa. Set aside.
Melt butter, bittersweet chocolate and white chocolate over low heat in a double boiler. Stir constantly until melted and remove from heat.
Beat eggs and sugar in a large mixing bowl until fluffy and light, about three minutes. Add chocolate mixture and beat until well combined.
Add flour mixture to chocolate mixture and beat until combined. Whisk in Guinness by hand (mixture may seem thin, don't worry).
Pour into prepared pan and sprinkle with semi sweet chocolate chips. Bake 25 to 30 minutes or until toothpick inserted in center comes out clean.
*Please note that this works best when beer is at room temp. Pour slowly to avoid foam, but if you do get foam, just spoon it off the top. Do not include foam in the measurements.
Recipe by Down Home Inspiration at https://www.downhomeinspiration.com/dessert-come-first-guinness-brownies/