Rhubarb and raspberry shortcakes

Zest the orange and rub the zest into the half cup of shortcake sugar until it looks like wet sand; set aside.

Combine white wine, water, sugar, a small pinch of kosher salt and vanilla extract in a large saucepan.

Juice the oranges to get half a cup of juice and add it to the pan.

Warm over medium heat, stirring, until the sugar is fully dissolved.

Split the thicker rhubarb stalks lengthwise and cut all of it into batons about an inch and a half long.

Add the rhubarb to the dissolved syrup and bring up only until very faint bubbling shows at the edges: not a simmer, never a boil.

Take off the heat, stir in the raspberries while the liquid is still warm, and set aside to cool.

Whisk the cake flour, zest sugar, kosher salt and baking powder together in one bowl.

Toss the frozen butter in the flour and grate it on a box grater straight into the bowl, working fast; toss the shreds to coat each one in flour.

Make a well, pour in the chilled heavy cream and stir to a shaggy dough, breaking up wet clumps and running the mixture through your hands to even out the hydration.

Turn out and flatten into a rough rectangle, compacting the sides with a bench scraper; roll to about a half inch thick slab.

Cut in half lengthwise and stack one half on the other; flour the surface and roll out again to a rectangle about twice as long as it is wide.

Cut in half crosswise, stack again, and roll out to a square about seven inches on all sides.

Trim the bare minimum from all four sides to expose clean cut edges, then cut three by three into nine squares.

Transfer to a parchment lined baking sheet and chill; about 15 minutes in the freezer while the oven preheats.

Preheat the oven to 425 with the rack in the middle.

Lift the fruit out of the poaching liquid with a slotted spoon into a bowl, leaving the liquid in the pan.

Boil the poaching liquid on high to reduce it to a syrup, about 20 minutes, then strain it.

Brush the chilled shortcakes with heavy cream, sprinkle with demerara sugar and poppy seeds.

Bake at 425 for around 20 minutes, rotating at the 15 minute mark, until the tops and bottoms are dark golden brown.

Whip the mascarpone with the remaining heavy cream; do not sweeten.

Split a cooled shortcake, spoon fruit onto the bottom half, drizzle with syrup, add a dollop of the cream and set the lid on top.