Into a large mixing bowl add the olive oil, pumpkin puree, eggs, sugar, brown sugar, vanilla extract, sour cream, salt, pumpkin pie spice, cinnamon, and nutmeg, and mix with a whisk until well combined.
Add the flour, baking powder, and baking soda, and mix it until the batter is just combined and there are no lumps of flour visible. Do not overmix.
Pour the batter into the prepared baking pan and bake the cake in a 180c (350f) preheated oven for about 50 minutes or until a toothpick inserted into the cake comes out clean with a few moist crumbs.
Allow the cake to reach room temperature for at least 1 hour.
Add the room temperature cream cheese and mix until smooth and creamy.
Top the room-temperature cake with the whipped cream cheese frosting and make swirls using an offset spatula. Sprinkle cinnamon on top and serve!
Notes
Use pure pumpkin puree in this recipe! It is very important that you use pure pumpkin puree in this recipe. Make sure that you are not using the presweetened or pre-spiced pumpkin puree. You will be able to find this information on the ingredient list of your pumpkin puree can.
Use room temperature ingredients. It is important that you use room-temperature ingredients. This step ensures that your mixture mixes into a homogenous mixture and bakes perfectly. you don’t want to place cold batter into the oven.
Don’t overmix the batter, you don’t want to develop the gluten in the flour. This step ensures you have moist cake and not dense and dry cake.
Test for doneness carefully. Use a toothpick or cake tester to check if the cake is done. Insert it into the center of the cake; it should come out clean or with just a few moist crumbs.
Line your baking pan with parchment paper! This step helps the cake to bake evenly, and it makes sure that your cake will release easily from the pan.
Measure your flour correctly! When measuring your flour, avoid scooping it with a measuring cup. Instead, stir the flour with a spoon to create as many air pockets as possible, and spoon it into your measuring cup. Finally, level it with a back of a knife.
Cool completely before frosting. Allow the cake to cool in the pan for 10 minutes, then transfer to a wire rack. Ensure it's completely cool before applying the cream cheese frosting to prevent melting.