Slowly caramelize white sugar in pan over medium heat. It may help to add sugar slowly as it starts to caramelize. This can be a little time consuming as it requires constant attention (or it can burn up).
Lightly oil ramekins with a neutral oil like canola oil. Pour hot caramel evenly into ramekins and allow to cool.
Blend eggs, vanilla, brown sugar and tahini in a large bowl.
Heat milk, cream and vanilla extract in a medium sauce pan on stove. Add hot milk while stirring to the blended eggs, brown sugar and tahini. Add the creme, mix and strain. Note: don’t forget to strain your custard or it will not be silky and smooth.
Bake covered with foil in a water bath at 325 degrees for about 20-25 minutes. To check, wiggle the pan. The center should just barely move, if so, then it is done. Remove from oven and allow to cool then refrigerate until well chilled.
To serve, unmold custards onto plate by inserting a thin knife between custard and ramekin and inverting onto a plate. If it sticks, lightly tap the sides and bottom of the ramekin.