Preheat oven to 350 degrees. Prep two baking sheets with parchment paper.
Beat butter and sugar in an electric mixer until creamy. Add melted chocolate, egg, and vanilla and blend.
Add flour, cocoa powder, brewer's yeast, flax seed, baking soda, and salt and mix until smooth.
Stir in oats and chocolate chips. The dough will be sticky.
Form dough into 1 inch balls and place on baking sheets about 1-2 inches apart.
Bake cookies for 9-11 minutes. Cookies will appear slightly underdone in the middle.
Let cookies rest for 5 minutes on the baking sheet and then transfer to a wire rack to cool.