In a large mixing bowl, beat together butter, granulated sugar, and light brown sugar using an electric mixer on medium speed for about 3-5 minutes until light and fluffy.

Add eggs one at a time, mixing thoroughly after each addition. Stir in vanilla extract until evenly incorporated.

Gently mix in pumpkin puree until fully blended.

In a separate bowl, whisk together flour, cocoa powder, baking powder, baking soda, cinnamon, nutmeg, cloves, and salt.

Gradually add the dry mixture to the wet ingredients and mix until just combined.

Fold in chocolate chips and nuts if desired.

Preheat oven to 350°F (175°C). Grease a baking pan or line with parchment paper.

Spread the batter evenly into the prepared baking pan.

Bake for 25-30 minutes until a toothpick comes out with moist crumbs.

Let cool completely in the pan before cutting into squares.