1. Reduce beer (minus 2 Tablespoons) in saucepan over medium heat until there is only 1/8 cup left. This will take 25-30 minutes. Watch the beer on the stove, as it will foam up easily at the beginning. Remove from heat and allow to cool.
2. Cream butter, brown sugar and espresso powder together until light and fluffy.
3. Add in eggs and reduced stout and mix until combined.
4. Turn mixer to low and add in baking soda, salt, flour and oats. Stir together until just combined.
5. Finally add in pretzels and chocolate chips, stirring until evenly incorporated.
6. Let dough chill for at least 2 hours, or overnight.

Frosting

1. In small saucepan heat butter and heavy cream over medium heat until just boiling.
2. Remove from heat and whisk in chocolate chips until smooth.
3. Add 2 Tablespoons reserved stout, stir to combine.
4. Chill frosting for an hour or two, until spreadable consistency.

Cookies

1. Preheat oven to 350°
2. Drop by heaping tablespoon size onto a parchment lined baking sheet, pressing dough slightly, so cookies aren’t so rounded.
3. Bake 9-10 minutes until golden around edges.
4. Transfer to a wire rack to cool.
5. When cookies are cooled and frosting is ready, spread on a teaspoon sized amount onto each cookie and top with a pretzel twist