Warm the oil in a frypan until it gets to medium-high heat. Dip one tortilla at a time in the oil and let it cook for 3 minutes. Make sure that you flip the tortillas every 15 seconds as you want them to have a homogeneous golden color.
You'll see that the tortilla starts to get harder. When it is totally crisp and golden, remove it from the oil. Repeat this with each tortilla.
Immediately after you remove them from the frypan, place the tortillas on a paper towel or paper napkin to drain the excess oil. You don't want to dry the tortillas, as buñuelos require a certain amount of oil to make them crunchy and flavorful. Also, they need that bit of oil for the sugar to get stuck to.
In a bowl, mix the cinnamon with the sugar.
Sprinkle the drained tortillas with the sugar and cinnamon mixture.
Save them once they are made. By all means, they are tastier, even though you can enjoy them cold. You can always keep them for a maximum of three days on a plate. You need to cover the buñuekos with paper or kitchen linen.