Key lime pie

Preheat the oven to 375F. Melt the butter over a mellow heat and set aside.

Put the graham crackers, sugar, milk powder and salt in a food processor and spin 30 to 45 seconds to a fine grind.

Add the melted butter and heavy cream and spin about 15 seconds until it comes together like damp sand. Scrape down and pulse five seconds more. It should compress in your hand.

Spray the pie plate liberally, tip in the crumbs and press them out evenly towards the edges and up the sides.

Compress into a cohesive crust with three fingers against a thumb, then use a cup measure to press the base and the sides hard. Overlap the crust slightly onto the outer rolled edge of the tin so it does not slough in.

With the crust about a quarter inch thick throughout, set the plate on a sheet tray and bake at 375F for 12 to 14 minutes until golden brown.

Whisk the condensed milk, egg yolks, sour cream, salt and key lime juice together in a medium bowl.

Cool the baked crust 5 to 10 minutes, then turn the oven down to 325F.

Pour the custard into the crust and wiggle it level.

Bake at 325F without convection for 15 to 19 minutes, until set at the edges with only the inner inch jiggling. Err towards more.

Cool to room temperature, then refrigerate covered overnight; at minimum two hours, preferably four.

Whip the cold heavy cream to stiff peaks, three to five minutes at seven out of ten, then add the pinch of salt.

On low speed, mix in the powdered sugar and vanilla extract.

Spread the whipped cream over the custard in an even layer, avoiding the crust, and swirl the top. Chill again before slicing for cleaner cuts.

Grate fresh lime zest over the top.