Step 2: Make the Filling

1. In a large mixing bowl, beat the softened cream cheese until smooth.
2. Add the powdered sugar, lemon zest, lemon juice, and vanilla extract. Beat until fully combined and smooth.
3. Spread the filling evenly over the chilled crust, smoothing the top with a spatula.

Step 3: Chill the Bars Cover the pan with plastic wrap and refrigerate for at least 4 hours (or overnight) to allow the filling to set.