In a food processor, combine flour, powdered sugar, almond flour, salt, and orange zest. Pulse until well mixed. Add chilled butter until it resembles coarse crumbs. Mix in egg yolk and cold water until dough comes together. Wrap in plastic and chill for 15-60 minutes.

Preheat oven to 375°F (190°C). Grease tart pan and roll out dough on a floured surface, fitting it into the pan. Chill for 30 minutes. Line with parchment, fill with weights, and bake for 12-15 minutes. Remove weights and bake until golden brown, then cool completely.

Heat the juice of fresh oranges in a saucepan until warm. In a bowl, whisk together egg yolks, superfine sugar, and cornstarch until smooth. Gradually whisk in orange juice, return to saucepan and cook over low heat, stirring constantly until thickened. Stir in gelatin, let cool slightly.

Pour the cooled orange curd into the tart shell, smoothing the top. Cover with plastic wrap and refrigerate for at least 3 hours, ideally overnight.

Whip heavy cream in a bowl until it starts to thicken. Add sugar and orange bitters, continuing to whip until stiff peaks form.

Garnish your Classic Orange Tart with whipped cream, fresh orange segments, or chopped pistachios. Slice and serve.