Preheat the oven to 350 F/180 C/ gas mark 4. Lightly grease a 23 cm (9 inch) square pan and line with baking paper. Set aside.
Combine the flour, baking powder, cacao, spices and salt and stir thoroughly using a whisk.
Melt the chocolate (almost completely) either in a microwave or in a heat proof bowl set over a pot of simmering water. Remove from the heat and stir until all the chocolate pieces have melted. Set aside to cool.
Beat together the sugar, eggs, oil and vanilla extract for 2-3 minutes until fluffy and pale. Gradually add the melted chocolate and mix to combine. Add the pumpkin puree and stir thoroughly using a whisk.
Pour in the flour mixture and chocolate chips and stir just to combine. Do NOT overstir.
Pour the batter into the pan and bake in the centre of the oven for 45 minutes. Remove from the oven, set aside for 10 minutes then lift out of the pan with the paper and place on a cooling rack. You can cut it when it's still a little warm.
Use either canned or homemade pumpkin puree. To make your own cut a small sugar/culinary pumpkin in half (through the top) and place on a baking sheet lined with paper cut side down. Bake in a preheated oven at 190 C for about 40-50 minutes or until the top browns and comes away from the flesh. Remove from the oven, discard the seeds, then scoop out the pulp and place in a strainer. It will release water as it cools. Once cooled puree and make the cake. You can prepare the puree in advance and refrigerate until you are ready to use it.
Use dark chocolate with 65-70% cocoa solids.
You can omit the spices in the recipe and use 1.5-2 teaspoon of pumpkin spice.
Once you've added the flour mixture into the batter stir just to combine. Do NOT overstir.
These brownies with pumpkin are best eaten a little warm. The chocolate chunks hidden in the batter will melt, seriously enhancing the deliciousness of this cake!