Always use full-fat cream cheese, never the spreadable variety. A higher fat content ensures the cheesecake sets firm and remains stable.
Whip the heavy cream until it forms stiff peaks before folding in the cream cheese. This adds structure and helps the filling not to sag when cut.
Allow your cheesecake to cool for at least 6–8 hours. Overnight is preferred. Cutting short this step results in a runny, unset center that refuses to hold shape.
Dissolve 1–2 teaspoons of agar-agar or gelatin in warm water and stir it into the filling. It functions like a setting agent, providing a firmer texture.
Crumb biscuits finely and blend with sufficient melted butter to make it hold together. Press into the pan hard so that the base doesn't crumble as you cut into the cheesecake.