Preheat oven to 350 F and prepare 9 x 9 baking pan with parchment paper.
To prepare brownies: Melt butter, add chocolate chips. Mix well. Cool of for 5 minutes. Add eggs, sugar and vanilla. Combine well. Add flour and mix with spoon or spatula.
To prepare pumpkin: In a medium bowl add butter and sugar and mix until fluffy with electric mixer. Add egg and mix. Add pumpkin puree and greek yogurt. Combine the batter well. Add dry ingredients: flour, baking powder, cinnamon and nutmeg. Mix with electric mixer until well combined.
In a 9 x 9 baking pan, make a dollops of the brownie batter, do the same with pumpkin batter. With knife swirl the batters so they will combine a little.
Bake for 20 - 25 minutes.
Any other sugar can be used instead of cane sugar.