Check that your cream cheese is fully softened. Press your finger into it and it should leave a clear indent without any resistance. Cold cream cheese will leave lumps in the dip that you cannot beat out, so do not skip this step. If it is still firm, microwave it in a bowl for 15 second intervals until it gives easily.

Beat the cream cheese in a large bowl with a hand mixer on medium speed for about 1 minute until it is completely smooth and fluffy with no lumps. Scrape down the sides of the bowl with a rubber spatula.

Add the pumpkin puree, brown sugar, pumpkin pie spice, cinnamon, and vanilla extract to the bowl. Beat on medium speed for another 1 to 2 minutes, stopping to scrape down the sides halfway through. The dip should look uniform in color with no orange or white streaks.

If you are using sour cream, fold it in now with the spatula. It thins the dip slightly and gives it a lighter, airier consistency. Taste the dip and adjust the brown sugar or spice level to your preference.

Transfer the dip to a serving bowl. For the best flavor, cover and refrigerate for at least 1 hour before serving. This resting time lets the spices bloom and the flavors meld together. Serve with cinnamon graham crackers, apple slices, or gingersnaps alongside.