- Combine mangoes and Sugar or canned mangoes with syrup in a heavy saucepan.
- Add triple sec and half of the lime juice and bring to a boil over medium-low heat.
- Simmer until mixture is very thick, stirring constantly toward the end.
- Stir in the butter, almonds, and as much of the remaining lime juice as needed to make the flavor sparkle.
- Set the mixture aside to cool. If refrigerated a day ahead of time, bring the filling back to room temperature before proceeding.
- Warm the tortillas for a few seconds on a griddle.
- Transfer them to a plastic bag to stay soft.
- Spoon one-fourth of the fruit mixture onto the center of a tortilla.
- Fold the sides in, and then roll up into a tight package, securing the chimichanga with wooden picks.
- Repeat with the remaining tortillas and fruit.
- Pour at least 3 inches of vegetable oil in a heavy, deep skillet.
- Heat the oil to 365 degrees F. Fry the chimichangas, one or two at a time, until light golden, 4 to 5 minutes.
- Drain and sprinkle with confectioners' Sugar shaken through a sieve.
- Serve immediately, topped with whipped cream if desired.