Maple Caramel

1 cup maple sugar
1/2 cup (1 stick) unsalted butter
3/4 cup heavy whipping cream
1/4 cup bourbon
1/4 teaspoon vanilla extract

Stir sugar and butter in heavy small saucepan over medium heat until blended and smooth. Whisk in cream. Bring to boil, stirring until caramel bits dissolve. Reduce heat to medium and simmer 5 minutes. Remove from heat. Stir in bourbon and vanilla; simmer 1 minute. (Can be made 3 days ahead. Cover and refrigerate.)