Pfirsich-Cheesecake (peach cheesecake)

Method

1. Crush the biscuits to fine crumbs and stir in the melted butter until it looks like wet sand. Press firmly into the base of a 22 cm springform, up an inch of the sides, and chill while you make the filling.
2. Wrap the outside of the tin in two layers of heavy foil, going right up over the sides, to keep water from a bath from seeping in through the springform seam.
3. Beat the cream cheese and sugar together until smooth, scraping the bowl down often; lumps at this stage never fully disappear later. Beat in the eggs one at a time on low speed, just until combined; overbeating adds air that later causes cracking.
4. Beat in the sour cream, cornstarch and vanilla, then fold in the diced peaches. Pour into the chilled crust and arrange the peach slices fanned over the top.
5. Set the wrapped tin into a larger roasting pan and pour boiling water into the pan to come halfway up the sides of the springform.
6. Bake at 150°C for about 70 minutes, until the centre still jiggles softly across an area about the size of a large coin and the edges look matte.
7. Turn the oven off, crack the door and leave it for 1 hour, then lift out of the water bath and cool fully at room temperature before chilling at least 5 hours, ideally overnight.

Notes

• The water bath is not a formality. Baked without one, this cheesecake sets unevenly, dries out at the edges long before the centre is done, and is far more likely to crack.
• Room temperature ingredients matter more than usual here. Cold cream cheese and cold eggs refuse to beat smooth and leave lumps that a water bath’s gentle heat will never cook out.
• Do not overbeat once the eggs go in. The extra air that a stand mixer whips into the batter is exactly what expands, then collapses and cracks the surface as the cake cools.
• It keeps for 5 days in the fridge, covered, and slices best when still cold from the fridge with a knife run under hot water between cuts.

Ingredient substitutions

• Peaches can be nectarines with no change, or apricots for a sharper, less sweet result; frozen peach slices work if thawed and well drained first.
• Sour cream can be crème fraîche or full-fat Greek yogurt in the same quantity, all giving a similar tang and body.
• Digestive biscuits can be any plain, not-too-sweet biscuit; shortbread works well and gives a slightly richer base.
• For individual cheesecakes, divide the crust and filling between a lined muffin tin and bake at the same temperature for about 22 minutes, skipping the water bath, which is unnecessary at that size.