Prep the pan. Lightly grease a 9 inch springform pan and, if you want easy removal, line the bottom with parchment.

Make the crust. In a bowl, mix graham crumbs, sugar, and salt. Pour in melted butter and stir until the texture looks like damp sand. Press firmly into the bottom of the pan and a little up the sides. Use a flat-bottomed cup to pack it in so it slices clean.

Chill the crust. Refrigerate while you make the filling, at least 15 minutes.

Start the filling base. In a large bowl, beat the room temperature brick-style (block) cream cheese until smooth and fluffy, about 1 to 2 minutes. Add powdered sugar and beat again until fully combined.

Add tang and flavor. Beat in sour cream, lemon zest, lemon juice, lime zest and lime juice (if using), vanilla, and a pinch of salt. Scrape down the bowl and mix once more. Taste. If you want more zing, add a little extra zest.

Whip the cream. In a separate bowl, whip cold heavy cream to stiff peaks. It should stand up when you lift the beaters. If it droops, keep going.

Fold, do not blast. Add whipped cream to the cream cheese mixture and fold gently with a spatula until no streaks remain. Keep it light and airy.

Fill and smooth. Spoon filling into the chilled crust and smooth the top. Tap the pan gently on the counter to settle any air pockets.

Chill to set. Cover and refrigerate for at least 6 hours, preferably overnight, until firm.

Serve. Release the springform ring. Slice with a hot knife (run it under hot water, wipe dry between cuts). Top with berries, lemon zest, or a spoonful of curd right before serving.