In a food processor, combine 1 ½ cups of all-purpose flour, ½ cup of powdered sugar, ¼ cup of almond flour, ½ teaspoon of salt, and the zest of one orange. Pulse until well mixed. Add 1 cup of chilled butter, pulsing until you achieve a texture resembling coarse breadcrumbs. Mix 1 egg yolk with 2-3 tablespoons of cold water, then add to the mixture, pulsing until combined. Shape the dough into a disk, wrap in plastic, and refrigerate for at least 30 minutes.

Preheat your oven to 200°C (390°F). After chilling, roll out the tart dough on a lightly floured surface to fit a 9-inch tart pan. Press it into the pan edges and trim the excess. To prevent bubbling, line the crust with parchment paper, fill with pie weights or dried beans, and blind bake for 12-15 minutes. Remove the weights and parchment, then bake for an additional 10-12 minutes until golden brown. Allow to cool completely.

In a small saucepan, gently warm about 300ml of fresh orange juice over medium heat. Whisk together 4 large eggs, ¾ cup of superfine sugar, and 2 tablespoons of cornstarch in a mixing bowl until smooth. Gradually incorporate the warm orange juice into the egg mixture to temper it, then return the mixture to the saucepan. Cook over medium-low heat, stirring constantly until thickened enough to coat the back of a spoon, about 8-10 minutes. Stir in 1 tablespoon of gelatin until fully dissolved.

Once the orange curd has cooled slightly, mix in 2 tablespoons of unsalted butter and an extra teaspoon of orange zest for enhanced flavor. Pour this luscious curd into the cooled tart shell, smoothing the top with a spatula. Refrigerate the assembled Classic Orange Tart for at least 3 hours, or ideally overnight, to allow it to set fully and the flavors to meld beautifully.

When ready to serve, beat 1 cup of heavy cream in a mixing bowl until soft peaks form. Gradually add 2 tablespoons of powdered sugar while continuing to whip until stiff peaks are achieved. To garnish, top the tart with the whipped cream just before serving, adding fresh mint leaves, orange segments, or crushed pistachios for an elegant finishing touch.