Preheat oven to 325°F (160°C). Grease a 9-inch springform pan or line a pie dish.

Beat cream cheese until smooth, then add sugar and beat again until creamy.

Mix in pumpkin puree, pumpkin pie spice, vanilla, and salt until combined.

Add eggs one at a time, mixing gently; fold in flour if using.

Pour into prepared pan and bake 35–45 minutes until center jiggles slightly.

Cool on a rack, then chill at least 4 hours before serving.