Add sugar to a heavy-bottom saucepan and place over medium-high heat. Cook for about 6 - 8 minutes, or until the sugar dissolves and the caramel is beautifully golden brown. Don't stir the sugar, but feel free to shake the saucepan in a circular motion from time to time to evenly distribute the sugar.
add the butter
When the sugar is dissolved and the caramel is dark and luscious, remove the saucepan from the heat and add small cubes of butter. Using a heat-proof rubber spatula, stir vigorously until the butter melts, then place back over medium heat. Stir continuously until the sugar and butter are incorporated, for about a minute.
the best salted caramel
While stirring with a rubber spatula or a metal spoon, gradually and slowly pour in the whipping cream. The saucepan should be on medium-low heat at this point. Stir until the ingredients combine, then bring to a boil. When the caramel starts to boil, remove from the heat and stir in the sea salt and lemon juice. Transfer the caramel to a glass jar and set aside until it comes to room temperature, then store in a fridge for up to 3 months. The caramel will thicken in the fridge and that's okay. You can always heat it in the microwave or on a stove before serving.