Whisk sugar and cornstarch in a wide saucepan.
Stir in water and orange juice.
Bring to a boil over medium-high heat, whisking constantly.
Once thickened, stir in cherries and orange zest.
Return to boil, then reduce heat to simmer 10 minutes.
Prepare ice cream in serving bowls.
Remove from heat, stir in cherry extract.
Pour brandy, and ignite with a long lighter.
Gently shake pan until flame has extinguished.
Spoon cherries over ice cream and serve immediately.