Wash and dry fruit thoroughly; remove stems and hull strawberries if large.
Thread fruit tightly onto bamboo skewers, leaving a short stick handle.
Line a tray with parchment paper or a lightly oiled silicone mat for cooling the coated skewers.
In a small heavy saucepan combine sugar and water; add vinegar and corn syrup or honey if using.
Heat over medium, stirring until sugar dissolves; then stop stirring and attach a candy thermometer.
Boil syrup until it reaches the hard-crack stage, about 150°C / 300°F; remove from heat immediately.
Hold a skewer by the handle and dip the fruit into the hot syrup, rotating to coat evenly.
Let excess syrup drip back into the pan, then place the skewer on the prepared tray to set.
Sprinkle sesame seeds or crushed nuts before the coating hardens, if desired.
Let the sugar shell cool completely until hard; serve within a few hours for best crunch.