In a large bowl, use a hand mixer to beat the cream cheese on medium/high speed until smooth. Add butter, vanilla, and pumpkin pie spice and beat until well combined and creamy or until desired consistency has been reached.
Reduce the speed to low and gradually sift in the powdered sugar. Increase speed to high and beat until fluffy, about 1-2 minutes.
Refrigerate for one hour prior to use.
Once the bars have completely cooled, drizzle the spiced cream cheese glaze on the top of the cake. Must be refrigerated.