Peel the bananas and slice each lengthwise into 3–4 pieces, depending on the size.
Place a banana slice and about 1 tablespoon ube halaya near the bottom edge of a wrapper. Fold the bottom over the filling, fold in both sides, and roll snugly. Seal with water or beaten egg.
Heat about 1 inch of oil in a pan over medium heat. Once hot, add the turon with the sealed side down. Fry in batches, turning until lightly golden.
Lower the heat slightly and sprinkle in the sugar. Keep turning until the sugar melts and coats the turon and the wrappers are golden and crisp.
Drain on a wire rack. Let cool for a few minutes before serving.
Notes
Saba bananas: Use ripe bananas. The riper they are, the sweeter your turon will be. Frozen saba or ripe plantains also work.
Ube halaya (purple yam jam): A thick, sweet ube spread. Homemade or store-bought works.
Lumpia wrappers: Use thin lumpia or spring roll wrappers for a crisp coating. Avoid thick egg roll wrappers.