Chocolate Fondant Tart

Crust

1. Move oven rack to lowest position.
2. Preheat oven to 400°F (200°C). Pulse flour, icing sugar, baking powder and salt in a food processor until combined. Add butter; pulse until pea-sized pieces form. Add yogurt; pulse until dough just comes together. Transfer dough from food processor to lightly floured surface and shape into a disc.
3. Roll dough into a 19 x 6-inch (48 cm x 15 cm) rectangle, about 1/8 inch (3 mm) thick. Transfer to 14 x 4-inch (35 x 10 cm) rectangular tart pan with removable bottom. Press dough to fit into pan and prick base with a fork; trim and discard any excess dough. Refrigerate for 30 minutes.
4. Bake on lowest rack until crust is golden brown, about 15 minutes. Let cool slightly.

Filling

1. Heat cream in a saucepan over medium heat until steaming; pour over chocolate in large heatproof bowl. Let stand for 1 minute; whisk until chocolate is melted and smooth.Whisk in sugar and eggs. Stir in flour until well combined; spoon mixture into crust.
2. Bake at 350°F (180°C) until filling is set at the edges but still very soft in the centre, 10 to 12 minutes. Serve warm.

Note: This chocolate tart freezes well once baked. Cool completely and cover with plastic wrap before freezing. Before serving, thaw completely, then reheat for 5 to 10 minutes at 350°F (180°C).