Set your oven to 325°F/165°C. Prepare a 9x9 square cake pan by giving it a light spray of vegetable cooking spray.
Pumpkin Swirl Mixture
Combine the pumpkin, cream cheese, sugar, vanilla, spice, and flour in a medium-sized bowl. Stir vigorously to combine. Use an immersion blender for stubborn cream cheese lumps.
If the batter is too thick, gently stir in one to two tablespoons of water.
Brownie Base
In a large bowl combine the brownie mix with the remaining ingredients.
Stir together until combined and no large lumps of flour remain.
Assembling the Brownies
Pour a little more than half of the brownie mixture into the bottom of the prepared cake pan.
Next, spread the pumpkin mixture over the brownie base, using a spatula to spread it out to the edges.
Spread the remaining brownie batter over the top. Optional: Add more chocolate chips on top.
Bake for 50 minutes. Check for doneness. If it's a little too soft in the middle, go ahead and cook it for 5 more minutes.
When the brownies are done, remove from the oven and cool for at least 30 minutes before serving. These brownies will firm up as they sit, so allowing more time to cool is even better.
In a large bowl combine the butter, peanut butter, and ½ cup of chocolate chips. Stir a little to ensure the chocolate chips are coated and then place this in the microwave for about 30 seconds. The chocolate chips should be soft enough to stir at the point. If not, microwave for another 10-15 seconds. Stir until smooth.Add the sugar, vanilla and pumpkin. Stir to combine.In a separate bowl combine the flour, cocoa, ground flaxseed, and cornstarch. Stir to combine. Add the flour mixture to the chocolate mixture. Stir until just combined (do not over mix).