Peel, core, and halve 6 pears
In a 20 cm ovenproof pan, melt 70 g butter
Add 55 g granulated sugar, 1 tbsp lemon juice, and 1 tbsp cognac to the butter
Cook over medium heat for a few minutes, stirring, until the mixture bubbles and turns amber
Add 1 tsp crushed cardamom and scrape vanilla pod, adding both the vanilla and pod to the caramel
Arrange the pears carefully in the caramel
Reduce heat to low-medium and cook for about 5 minutes, watching closely so the caramel doesn't burn
Remove the pan from heat and let it cool briefly
When warm rather than hot, cover the pears with a sheet of puff pastry and prick a few small holes
Bake at 200°C (400°F) until the pastry is puffed and golden
Remove from oven and let rest for about 30 minutes
While the tarte rests, whip 200 ml sour cream together with 2 tbsp powdered vanilla sugar until airy
Grate lemon zest and add to the sour cream, taste and adjust seasoning
Flip the pan onto a serving plate, warming briefly on the stovetop if it sticks
Serve with the whipped sour cream
