Caramel Bourbon Vanilla Sauce

Combine sugar and water in a 2-quart saucepan over medium heat. Without stirring, cook until dark amber in color, swirling pan carefully while cooking, about 20 minutes. Reduce heat to low. Slowly add cream, stirring with a wooden spoon. Scrape seeds of vanilla bean into pan; add pod. Add lemon juice, butter, and bourbon. Stir to combine. Store in an airtight container, refrigerated, up to a week. Bring sauce to room temperature, or warm over low heat, before using.