In the bowl of a stand mixer or a large bowl with a hand mixer, cream butter and brown sugar together until light and fluffy.
Mix in vanilla and salt.
Slowly beat in cocoa powder and flour until combined. Mix in buttermilk.
Add red food coloring and mix until combined.
Fold in mini chocolate chips.
Store in an airtight container in the fridge. Cookie dough should stay fresh for 5-7 days when stored properly.