Preheat the oven to 325°F (160°C).
In a large bowl, beat the cream cheese until smooth.
Add sugar and vanilla extract, mixing until well combined.
Incorporate eggs one at a time, mixing well after each addition.
Stir in sour cream and flour until smooth.
Divide the batter into three bowls.
In one bowl, mix in the blueberries to create a blue batter.
In another bowl, mix in the strawberries to create a red batter.
In the last bowl, keep the batter white.
In a greased springform pan, alternate pouring the red, white, and blue batters to create a swirl effect.
Bake for 50-60 minutes or until the center is set.
Let cool, then refrigerate for at least 4 hours before serving.
