Preheat the oven to 200°C (392°F) and line a baking sheet with parchment paper.
Peel, core, and thinly slice the apples. Drizzle with lemon juice to prevent browning.
Roll out the puff pastry sheet on a lightly floured surface and cut out 7-8 circles or squares.
Place the puff pastry circles on the prepared baking sheet.
Gently heat the apricot jam to make it more spreadable. Brush a thin layer of the warmed jam onto the puff pastry circles.
Arrange the apple slices in a fanned pattern on the puff pastry circles, leaving a small border around the edges. Roll up the edges slightly and brush with egg yolk.
Mix the brown sugar with the cinnamon and sprinkle over the apples.
Bake the tartes in the preheated oven for about 15-20 minutes, until the puff pastry is golden brown and the apples are tender.
Remove the tartes from the oven and let them cool slightly. Brush with more apricot jam or maple syrup.
