Combine sugar and water. Pour the water into a heavy-bottomed saucepan, then carefully pour the sugar into the center of the pan (try not to let any crystals touch the sides). Gently stir just once to combine, then stop stirring—this helps prevent crystallization. ½ cup (120 mL) water 1 cup (200 g) granulated sugar
Boil until amber. Place the pan over high heat, cover, and bring the mixture to a boil. Once it’s boiling, uncover and continue to cook without stirring. Watch closely as the syrup thickens and begins to change color. When it turns a deep amber color (like honey or dark maple syrup), remove it from the heat immediately.
Add the cream carefully. Once the caramel reaches that amber stage, carefully pour in about a quarter of the warm cream. It will bubble up vigorously—just let it settle before slowly adding the rest of the cream. ½ cup (120mL) heavy cream
Finish the sauce. Whisk gently until smooth, then whisk in the butter, vanilla, and salt. The caramel will look thin at first but will thicken beautifully as it cools. 1 Tablespoon unsalted butter 1 teaspoon vanilla extract 1 teaspoon salt
Cool and store. Let the sauce cool until warm, then serve or transfer to a jar. Store in the refrigerator for up to 2 weeks. The caramel will be thin at first and thicken as it cools. The caramel will thicken as it sits in the refrigerator. Just re-heat in the microwave to warm it back up and be able to drizzle.