Melt the butter in the microwave. Place the cookies for the crust in a food processor and pulse until finely ground. Mix the melted butter with the cookie crumbs, then press the mixture firmly into the bottom of your chosen pan using a spatula. Chill in the refrigerator.

Pour 1 2/3 cups milk (400 ml) into a saucepan and heat it. In a separate bowl, mix 3/4 cup milk (200 ml) with the custard powder and stir until dissolved. Set aside.

In another bowl, mix 2/3 cup milk (150 ml) with the cuajada powder and stir until completely dissolved with no lumps. When the milk in the saucepan starts to boil, reduce the heat and add the dissolved custard mixture, the dissolved cuajada, and the sugar. Whisk constantly until the mixture comes back to a boil, about 1-2 minutes.

Pour the mixture into the prepared pan and let it cool slightly. Then refrigerate for at least 4 hours, or preferably overnight.

Before serving, prepare the topping. Whip the heavy cream with the powdered sugar until stiff peaks form. Pipe the whipped cream over the cake using a piping bag.