1. Preheat the oven to 325°F (160°C). Grease a 10 inches (25cm) tart tin lightly and set aside. Melt the butter for the crust and let cool down again.

 

2. Add the Oreos to a freezer bag and crush with a rolling pin until you get very fine crumbs. Add the melted butter and sugar and mix until well combined. Pour the crumbs into the prepared tart tin and press to the bottom and sides to create a nice crust – the back of a spoon or a glass/cup with straight sides works best here. Set aside.

 

3. Chop the chocolate for the filling and add to a large heatproof bowl. Add the heavy cream and milk and place over a pot with simmering water. Heat up gently until the chocolate has melted and you got a smooth chocolate sauce. Remove from the heat and let cool down a bit. Add the egg and egg yolk to a large bowl and whisk until light and fluffy. Gradually add the slightly cooled chocolate and mix in. Pour the filling into the prepared crust and bake for about 25 minutes until the filling has set. Take out of the oven and let cool down completely.

 

4. For the caramel add the sugar to a small saucepan. Heat up over medium-high heat until the sugar starts to melt. Tilt the saucepan slightly so the sugar melts evenly. When the sugar has melted completely and has a slightly golden color, add the butter. Be careful – the mixture will start bubble up a lot. Mix everything with a wooden spoon until the butter has melted completely and everything is well combined. Add the heavy cream – it will bubble up once more – mix until well combined. Add the salt and mix in. Remove from the heat and let cool down for 20-25 minutes. Pour the caramel on top of the chocolate tart – you can just add some to the center of the tart (and save the rest for something else) or spread it all over. Place in the fridge for about 1 hour. Sprinkle with flaky sea salt before serving.