Boil 2 cans of sweetened condensed milk over medium heat for about 2.5 hours. Afterwards, set aside to cool.

Preheat the waffle.

Melt butter in a large bowl and put aside. Beat the sugar and eggs well (without separating them). Add the egg-sugar mixture to the melted butter, along with a teaspoon liqueur (or brandy) and beat everything together very well (you can use a mixer).

Mix the baking powder and the cup of flour. Slow mix flour to the mixture, whisking constantly until smooth.

On the heated waffle, add a large tablespoon of dough, close the waffle maker and bake until browned. Very quickly roll the waffles into tubes while they're still hot because later they will be too fragile to shape. To reduce the chance of burning your hand, you can use clean, disposable kitchen gloves.

For the filling, mix the cooled boiled sweetened condensed milk (the dulce de leche) very well with the room temperature butter and a couple of teaspoons of liqueur.

Stuff the cooled wafers with the filling using a pastry bag, or if you don't have that on hand, just a small bag with one corner cut off.

Enjoy!