In a saucepan, combine sugar and 1/4 cup water. Cook over medium-low heat, stirring with a wooden spoon, until sugar has dissolved. Cover; bring mixture to a boil. Keep covered, about 1 minute, to let condensation wash down inside of pan to prevent crystals from forming (or wash down sides of pan with a wet pastry brush).
Raise heat to medium-high. Without stirring, cook, swirling pan, until mixture turns a medium to dark amber. At arm's length, carefully add cream (it will spatter). Add vanilla-bean seeds to pan, and whisk to combine. Transfer to a fondue pot, and set over a warming candle. Serve immediately with assorted accompaniments, as desired.