- Preheat oven: Set the temperature to 350°F and prepare two baking sheets with parchment paper now. 
- Cream butter and sugar: Beat softened butter with brown sugar until a light and fluffy mixture forms. 
- Add wet ingredients: Mix in pumpkin puree, egg, and vanilla extract until completely smooth and combined. 
- Whisk dry ingredients: Combine flour, cocoa powder, baking soda, and salt in a separate large bowl. 
- Combine mixtures: Gradually stir dry ingredients into the wet mixture until just combined without any overmixing. 
- Add chocolate chips: Fold in chocolate chips gently, distributing them evenly throughout the cookie dough. 
- Scoop dough: Drop rounded tablespoons onto prepared sheets, spacing them about two inches apart for spreading. 
- Bake cookies: Place in preheated oven and bake for 10-12 minutes until edges are set. 
- Cool properly: Let cookies rest on the baking sheet for five minutes before moving to a rack. 
- Serve and enjoy: Wait until completely cool, then serve these delicious double chocolate pumpkin treats IMMEDIATELY!