Step 1 In a medium saute pan, combine the sugar and water. Add the lemon juice and heat the pan over medium-high heat. Do not stir the pan as the sugar melts and starts to bubble; this can cause the sugar to become lumpy and crystallize. If the sugar crystallizes, you will have to start over.
Step 2 Once the sugar begins to turn a rich brown, gently swirl the caramel by moving the handle of the pan. Continue to cook the caramel until it is a rich, dark brown. Keep in mind that the caramel will look darker in the pan than it actually is. Be careful not to overcook the caramel, or it will blacken and burn.
Step 3As soon as the caramel is ready, remove it from the heat and pour the caramel into a 10-inch cake pan to coat the bottom of the pan. Swirl the cake pan to coat the bottom evenly.
Step 4Place the cake pan on a flat surface and set aside until the caramel is cool.