The richness required for a gooey, custard-like middle is provided by full-fat cream cheese and cream.
To avoid too much air, which could give the mixture a harder, less creamy feel, avoid overmixing.
Maintain the gooey center while baking at high heat for a richly caramelized crust.
To keep the center moist and gooey, shorten the baking time by a small amount.
For a smoother batter that bakes evenly and maintains its creaminess, use ingredients that are at room temperature.