This recipe requires careful preparation of the sugar syrup and gentle tempering of the egg yolks to prevent curdling. The result is a thick, glossy, and incredibly smooth cream.
A large amount of sugar is traditionally used, serving not only to sweeten but also as a preservative and to achieve the correct texture. Properly cooked Ovos Moles cream should be sliceable with a knife when chilled.
In a large saucepan, combine sugar and water. Heat, stirring constantly, until the sugar is completely dissolved.
Increase the heat and boil without stirring until the syrup reaches 105 °C (221 °F) (the 'soft ball' stage). This takes approximately 10-15 minutes. If you do not have a thermometer, the syrup should be thick and bubble with large, slow bubbles.
Remove the syrup from the heat and let it rest for a moment.
In a bowl, lightly whisk the egg yolks with a fork – do not whisk for long; we do not want foam or air bubbles to form.
Very slowly pour a ladleful of hot syrup into the bowl while constantly whisking the yolks to temper them. This step prevents the eggs from scrambling when you pour them back into the pot.
Slowly pour the entire tempered egg yolk mixture back into the pot with the remaining syrup, stirring constantly.
Return the pot to low heat and cook for 10-20 minutes, stirring constantly with a wooden spoon or spatula. The cream will visibly thicken and darken to a deep yellow colour. CAUTION: The cream must not boil (the temperature should not exceed 85 °C / 185 °F), otherwise the yolks will curdle. If the cream starts to boil, remove it immediately from the heat.
Once the cream has thickened sufficiently (it should separate from the sides of the pot), transfer it to a clean, cold bowl, cover it with plastic wrap directly on the surface to prevent a skin from forming, and let it cool completely.
Once cooled, the Ovos Moles is ready to eat. If you want the traditional form, fill prepared wafers with it. The cream is also ideal as a filling for cakes or served alone with a spoon as a luxurious dessert.