Combine the sugar, brown sugar, and syrup in a medium saucepan on medium heat, stirring every few minutes to keep the sugar heating evenly, but don't stir constantly. Cook until it becomes fluid and deep caramel color.
Add the butter off the heat (The mixture will bubble rapidly so be careful) stirring constantly with a whisk until combined completely into the sugar mixture. There should be no visible butter so whisk quickly to combine and keep whisking until it is thoroughly combined (This can take 3 or 4 minutes).
Very slowly stir in the heavy cream and vanilla until combines. Allow to cool before using. Caramel thickens as it cools.
Cover tightly and store for up to 1 month in the refrigerator. Caramel will solidify in the refrigerator. Reheat in the microwave or on the stove to the desired consistency.
This recipe makes approximately 1¼ cups of caramel. Serving five servings of a ¼ cup/60ml serving.TIPS
Use good quality butter for best results. This is one of those times I recommend using European butter which has a higher fat content and less water.
Work carefully caramel gets very hot as it cooks. If you’re worried about splatter, I recommend using heatproof gloves to avoid burns.
If the butter looks like it’s separating or if the sugar clumps, whisk quickly to combine it again (keep whisking until it is thoroughly combined).
When cooking down the sugar, keep an eye on it to make sure it does not burn.
The mixture will vigorously bubble when adding the butter and cream so don’t worry, you’re doing it right (but be careful – it’s hot)!
For salted caramel, just add a teaspoon of salt at the end