Put the flour in a mixing bowl. Knead cold fat in flakes, sugar, salt, egg yolk, hazelnuts and cinnamon to a smooth shortcrust pastry. Cover the dough and chill for about 30 minutes. Roll out the short pastry on a floured work surface to a circle (28 cm Ø). Grease a tart tin or springform pan (26 cm Ø). Put the dough into the tin, press it lightly and prick it several times with a fork.
Cut out a circle (approx. 30 cm Ø) from the baking paper, place it on the shortcrust pastry and spread dry peas on top. Bake in the preheated oven (electric cooker: 200 °C/ gas: level 3) for about 20 minutes. Remove dry peas with baking paper. Bake for another 10-15 minutes and let cool off. Remove from the tin. Heat up the orange marmalade and pass through a sieve. Spread the shortcrust pastry base with 5-7 tablespoons of jam. Peel oranges so that the white skin is completely removed. Cut out orange fillets between the parting skins and let them drain well on a sieve. Cover the tart with orange fillets. Warm the jam again briefly and spread over the oranges.
Heat up the orange marmalade and pass through a sieve. Spread the shortcrust pastry base with 5-7 tablespoons of jam. Peel oranges so that the white skin is completely removed. Cut out orange fillets between the parting skins and let them drain well on a sieve. Cover the tart with orange fillets. Warm the jam again briefly and spread over the oranges. Roast the hazelnut leaves in a pan without fat and sprinkle over the tarte. Makes 12 pieces