01 -
Using an electric mixer, beat the softened butter with the icing sugar until you get a smooth, creamy consistency - this takes about 2 minutes. Pause to scrape down the sides of the bowl when needed. Add the egg and ground almonds, mixing until you have a thick, somewhat grainy paste. Toss in the flour and salt, then mix on the lowest speed just until everything clumps together into a shaggy dough - don't overwork it or the pastry will become tough.
02 -
Shape the dough into a ball with your hands, then sandwich it between two large pieces of parchment paper. Flatten it down with your palm first, then use a rolling pin to roll it out into a circle about 4mm thick. Transfer the whole thing (paper and all) onto a baking sheet and pop it in the fridge for at least an hour, though you can leave it up to a full day if that works better for you.
03 -
Take the chilled dough out and let it sit for a few minutes until it's pliable but still cool. Peel away the parchment and carefully lay the pastry into a 24cm tart pan. Gently work it into the corners so it sits at a nice right angle where the base meets the sides. Trim away any overhang with a sharp knife. Return the lined pan to the fridge for another 2 hours minimum - overnight is even better.
04 -
Heat your oven to 160°C. Use a fork to prick holes all over the base of the pastry, then stick it in the freezer while the oven finishes heating up. Bake for 40-45 minutes until the crust turns a light golden color and feels completely dry to the touch. Let it cool entirely on a wire rack.
05 -
Blend your raspberries (make sure frozen ones are fully thawed and drained) until silky smooth using either a regular blender or a stick blender. Set a fine-mesh strainer over a medium saucepan and pour the puree through, using a spatula to push it through while leaving the seeds behind. Toss out what doesn't go through.
06 -
Whisk the egg yolks and sugar into the raspberry puree, then stir in the cornstarch. Put the pan over low heat and stir constantly with a heatproof spatula for 3-4 minutes until the sugar dissolves and the mixture just begins to thicken slightly. Drop in the butter piece by piece, whisking after each addition until it melts completely. Keep cooking and stirring for about 5 more minutes until the curd becomes thick enough to coat the back of your spatula. If you want it extra smooth, strain it one more time to catch any stray seeds or bits of cooked egg.
07 -
Pour the warm raspberry curd directly into your cooled tart crust and use a small offset spatula to spread it evenly across the bottom. Refrigerate for 1 hour - it should firm up a bit but still have some give when you touch it.
08 -
Rinse your fresh raspberries and dry them thoroughly. Press them gently into the set curd with the hollow centers facing upward. If you're using the jam, spoon it into a piping bag and snip a tiny opening at the tip. Pipe a small amount of jam into the center of each raspberry. Return the finished tart to the fridge for 2-3 hours so the curd sets up completely before you slice and serve.