- In a small saucepan, combine sugar and water over medium heat, stirring until the sugar dissolves completely. 
- This should take about 3-4 minutes. 
- Increase the heat to medium-high and stop stirring. 
- Let it boil until the mixture turns a deep amber color. 
- Carefully remove from heat and slowly add the heavy cream while stirring. 
- It might bubble up, so pour gradually to avoid splattering. 
- Add vanilla extract and stir until smooth. 
- Return to low heat and simmer for about 5 minutes, stirring occasionally. 
- Remove the sauce from the heat and let it cool before transferring it to a jar. 
- The sauce will thicken as it cools.