Preheat the oven to 350 degrees . In a medium saucepan over high heat, add the sugar and pour 2/3 cup water around the perimeter. Using a wooden spoon, cook, stirring, until golden, about 5 minutes. Lower the heat and cook until copper-colored, 1 to 2 minutes. Pour into a 10-inch deep-dish pie plate; using potholders, tilt to coat the bottom and the sides, then place in a roasting pan on an oven rack.
Using a blender, combine the remaining ingredients and pour into the pie dish. Fill the roasting pan with enough water to come halfway up the sides of the pie dish. Bake until set, 45 to 60 minutes. Transfer the pie dish to a rack to cool completely, about 45 minutes. Refrigerate until the caramel is set, about 2 hours. Invert onto a plate before slicing.