Metal Molds or a mold

• Split the vanilla pods lengthwise, but do not extract the pulp yet.
• Heat the milk, butter, vanilla pods, liquid vanilla extract, and rum over low heat in a saucepan until it starts to boil. This may take about 10 minutes.
• Remove the saucepan from the heat and let the mixture sit, covered, for 15 minutes to allow the flavors to integrate. Set aside.
• In a bowl, mix the whole eggs, yolks, and sugar, stirring until you achieve a smooth, yellow cream. You can do this with a stand mixer equipped with the whisk attachment.
• Remove the vanilla pods from the milk and scrape out the pulp with a knife.
• Add the vanilla pulp to the bowl with the eggs and sugar. Stir well until combined.
• Place the empty vanilla pods back into the milk to continue infusing.
• Gently reheat the milk over low heat until small bubbles form, but do not let it boil.
• Remove the milk from the heat and let it sit uncovered for 3 minutes to cool slightly.
• Add 1/4 of the hot milk to the egg and sugar mixture, stirring well. The milk should be very hot but not boiling.
• Incorporate the sifted flour into the mixture, stirring at low speed to avoid introducing air.
• Add the remainder of the hot milk and mix until a liquid and homogeneous batter is obtained.
• Cover the batter with cling film in contact with the surface and let it rest for 24 hours in the refrigerator to ensure the proper texture.
• The next day, remove the dough from the refrigerator about 2-3 hours before making the canelés so that it reaches room temperature.
• Completely butter the molds, sprinkle sugar on the bottom and sides, and place them in the refrigerator for at least 1 hour before baking.
• If using a nonstick spray, apply it to the molds and place them upside down on absorbent paper shortly before baking; in this case, there's no need to refrigerate them.
• Preheat the oven to 270 ºC for 30 minutes before baking.
• Note: If the mold is silicone, preheat the oven to 220 ºC, as silicone cannot withstand higher temperatures.
• Remove the tray from the oven and place the support rack in a middle position inside the oven.
• Take the molds out of the fridge if you have refrigerated them, or apply the nonstick spray.
• Remove the vanilla beans from the paste and stir for 2 minutes to reintegrate any butter that may have separated.
• Place the molds on a flat baking tray.
• Fill the molds up to 2 mm from the edges to prevent the batter from overflowing while baking.
• Bake the canelés until the top is golden and crispy, following the specific instructions for the molds you are using.
• If using metal molds: bake at the indicated temperature and time, as specified below.