1. Mix the flour with confectioners‘ sugar and salt in a large bowl. Add the cold butter in small pieces and cut with a knife or pastry cutter into pea-sized pieces. Add the egg and mix with your fingers until the dough comes together. Wrap in plastic wrap and place in the fridge for about 30-40 minutes.

2. Preheat the oven to 180°C (350°F). Add the sour cream, heavy cream, and vanilla extract to a large bowl and mix until well combined. Mix the sugar with the flour and add to the bowl, mix in. Whisk the eggs, add them to the bowl and mix in as well until you get a smooth mixture. Set aside. Mix the sugar and cinnamon and set aside.

3. Line a springform tin or pie dish (10 inches) with baking parchment and grease lightly. Roll out the dough on a floured surface to a round slightly larger than the tin. Transfer to the tin and press to the bottom and sides – the edges should be at least 1.2 inches high. Prick the bottom several times with a fork, then pour the filling into the prepared base. Bake for about 40-45 minutes until the cake got some nice color and is wobbling only slightly in the center when moved. Take it out of the oven and immediately sprinkle it with the sugar-cinnamon mixture. Let it cool down completely in the tin.