In a large bowl, add sweetened condensed milk, pumpkin puree, cinnamon, and eggs. Whisk until smooth. 1 can sweetened condensed milk, 2 cups pumpkin puree, 1 tsp cinnamon, 2 eggs
Evenly spread half of the brownie batter into the prepared baking pan. Make sure the entire bottom is covered well or else the pumpkin will leak through. Pour pumpkin mixture on top and use a butter knife to gently swirl the top. Don't over mix!
Add the remaining brownie batter and lightly swirl.
Bake the brownies at 350°F for 55 minutes up to 1 hour 10 minutes. These brownies take much longer than your average recipe due to the pumpkin. You'll know it's ready when a wooden skewer inserted comes out of the center with a few crumbs.
Allow to cool completely. Towards the end, make the chocolate ganache by melting together the heavy whipping cream and chocolate chips in a microwave or on the stove.
2 tbsp heavy whipping cream, 1/2 cup dark chocolate chips or bar
Drizzle chocolate ganache. Set, slice, and enjoy!