01 -
Heat your oven to 350°F (175°C). Place the puff pastry sheets on separate trays and bake for 10 minutes. Let them cool until room temperature.
02 -
Take 3 cups of milk and bring it to a gentle boil in a saucepan set to medium heat.
03 -
Whisk the sugar and egg yolks in a large bowl until the color turns pale, and the texture gets fluffy.
04 -
Add the plain flour, vanilla, optional rum, pinch of salt, and the last 1 cup of milk to the egg-sugar mixture. Stir everything until smooth with no lumps.
05 -
Slowly pour the egg mixture into the boiling milk while stirring all the time. Cook and mix until it gets thick enough to coat the back of your spoon.
06 -
Use a mixer to beat the egg whites in a separate clean bowl until you see stiff peaks. Carefully fold the egg whites into the warm custard to make it light.
07 -
Put one of the now-cooled puff pastry sheets inside a 9×13-inch pan. Spread the creamy custard evenly over the pastry.
08 -
Place the dish in your refrigerator for 1 to 2 hours to allow the custard to firm up.
09 -
Once the custard layer sets, whip the chilled heavy cream with powdered sugar in a mixing bowl until it holds stiff peaks. Spread it across the custard layer evenly.
10 -
Slice the second puff pastry into 15 neat squares and arrange them gently on top of the whipped cream layer.
11 -
Chill the entire dish in your fridge again for about 2 hours to fully set.
12 -
Sprinkle some powdered sugar over the top if you'd like, and cut into 15 equal squares to serve chilled.