Line the bottom of an 7-inch (18 cm) springform pan with parchment paper. (You can also use an 8-inch (20 cm) pan.) Prepare the crust: Crush the cookies and mix with the melted butter. Stir well until you have a sandy mixture, then press it into the bottom of the pan using the back of a spoon. Place in the fridge while you prepare the filling.

Heat the milk, reserving two small cups. Dissolve the flan mix in one cup and the cuajada in the other. When the milk starts to boil, add both mixtures along with the sugar. Stir constantly with a whisk until it thickens, then remove from heat. Carefully pour the mixture over the cookie crust in the pan (I pour it gently over the back of a large spoon).

Arrange the chocolate cookies on top of the cake in a spiral pattern and let it cool. Refrigerate for 4 to 5 hours until fully set. Remove from the fridge just before serving. It's delicious and so quick to make—I highly recommend it! https://dulcestentacionesdemarlen.blogspot.com.es/2017/10/tarta-de-natillas-y-galletas-de.html