Preheat oven to 350°F (177°C). Line an 8 x 4 inch loaf pan with parchment paper.
In a large microwaveable bowl, add chocolate chips. Heat in 15-30 second intervals, stirring in between with a spatula, until chocolate is completely melted and smooth. You can also melt the chocolate on the stove using the double boiler method.
Add in the pumpkin puree and stir until it is completely and evenly incorporated into the chocolate. If adding additional chocolate chips or chopped chocolate, add it in now and stir until evenly mixed. You can also reserve some of the chocolate chips to sprinkle on top of the batter.
Pour batter into prepared pan. Bake for about 20-30 minutes or until done (mine was done at 25 minutes). When batter is done, the surface should look like cooked brownies. When you insert a toothpick, the brownie batter should not be liquid but also should not come out clean. What sticks to your toothpick should look like moist crumb rather than uncooked batter.
Let brownies cool fully before cutting (at least one hour), otherwise the brownies will fall apart when you try to cut them. The brownies will be very fudgy with slightly cakey edges if you eat them the same day they are baked. The next day, the brownies become more dense and chewy. I like them both ways. You can also reheat them briefly in the microwave if you want the leftovers to get back to the just-baked texture.
Notes
These brownies are not super sweet. They are like dark chocolate and have a bittersweet flavor. Their crumb is also more delicate than traditional brownies. See post for more details on brownie sweetness and texture.
I added chopped chocolate to my brownies but it's completely optional. It does add some more sweetness to the brownies though. You can mix-in semisweet chocolate chips, milk chocolate chips or white chocolate chips. Or you can roughly chop up a chocolate bar like I did. I mixed in 3 tbsp of chopped chocolate and sprinkled an additional heaping 1 tbsp of chopped chocolate on the surface of the batter before baking. Please note white and milk chocolate can only be used as mix-ins, they can't be used to make the brownie batter.
The cooking time can vary depending on if you add mix-ins, how moist your pumpkin puree is and the brand of semisweet chocolate used. It is a little tricky to know when the brownies are done because a toothpick should not come out clean. You want the batter that clings to the toothpick to look thick and almost like moist brownie crumb rather than liquid uncooked batter.
Please let brownies cool completely before eating otherwise they will fall apart when you try to cut them.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.