In a small saucepan, combine the brown sugar, cinnamon stick, lime peel, and 1 cup of water. Bring to a gentle boil over medium heat, stirring occasionally, until the sugar has dissolved. Allow it to simmer for about 10 minutes until it slightly thickens. Remove from heat and set aside to cool.
In a large mixing bowl, whisk together the eggs and milk. Mix in the melted salted butter, salt, and lime zest. Gradually add in the sifted all-purpose flour and mix until just combined; a few lumps are okay!
In a frying pan or deep fryer, heat the oil until it reaches about 350°F (175°C). You can test the oil by dropping a small amount of batter into it; if it sizzles and rises to the surface, it’s ready.
Using a tablespoon, carefully drop spoonfuls of the batter into the hot oil. Fry in batches, making sure not to overcrowd the pan. Cook for about 2-3 minutes on each side or until they turn golden brown and puffy. Use a slotted spoon to remove them from the oil, and place them on a plate lined with paper towels to drain any excess oil.
Once the buuelos have cooled slightly, dip them into the prepared syrup, ensuring they are well-coated. Let them soak for a minute to absorb all that sweet goodness.
Dust the buuelos with cinnamon powder and serve them warm. Enjoy your homemade Buuelos de Viento with a cup of coffee or tea!