Put the pumpkin pie spice, pumpkin puree, and sweetened condensed milk in a bowl.
Stir the three ingredients together for a while
If you notice lumps in the mixture, you can get rid of them by whisking the ingredients
Once you achieve a smooth consistency, transfer the pumpkin spice sauce into a mason jar and refrigerate it
You can use a tablespoon of this in your favorite drink like a latte, coffee, or frappuccino
Remember to refrigerate the remaining sauce so that it remains fresh until the next time you need it