Make the caramel. In a small pan over medium-high heat, add 1 cup of sugar. Gently stir the sugar around with a spoon. The sugar will form lumps. Keep stirring until most of the lumps have melted. This can take anywhere from 8 to 10 minutes. Once there's not a lot of sugar lumps left, turn off the heat but keep stirring until the caramel is smooth and lump free.
Once the caramel is finished, pour it into your mold, but be very careful because the caramel will be very hot. Use a 9×3 round mold or a flanera. Set it aside until the quesillo mix is ready.
In a blender, add the milk, eggs, condensed milk, dry milk, vanilla extract, brandy, and sugar. Blend for 2 minutes on high speed. Strain the quesillo mix over the mold with the caramel. Cover the mold with foil so no water goes in.
Put the mold in a bigger mold or pan to make a bain marie or water bath. Center the mold in the middle and add hot water until it reaches about halfway up the mold.
Plate the water bath in the oven. Cook for 1 hour and 30 minutes. Take the quesillo out of the oven and out of the water bath, and let it rest for 30 minutes at room temperature. Uncover the quesillo and insert a toothpick in the middle to check for readiness. The toothpick should come out clean.
Refrigerate for at least 2 hours. When ready to serve, take it out of the fridge. If needed, run a knife around the border of the mold. Place a larger plate on top of the mold and quickly flip it.
Lift the mold, cut, and serve. Buen provecho!
Notes
Caramel- The caramel is very simple to make. Just make sure to constantly stir, so it won't burn.
Cooking time- The quesillo takes 1:30, but this is specifically in a 9x3 mold. If you have a smaller but taller mold, it can take longer. Make sure to test it after baking to make sure it is cooked.
Flan- The quesillo is very similar to the traditional Puerto Rican flan, but the texture is different. Some of the ingredients are also different.