Preheat the oven to 325°F. Place the ramekins in the roasting pan and set aside.
Pour the sugar into a large skillet and add the water. Place over medium heat and cook without stirring until the sugar becomes liquid and turns a medium shade of amber.
1½ cups granulated sugar, 1 tbsp water
Take the caramel off of the heat immediately and, working quickly, pour a little of the caramel into each ramekin. Swirl the ramekins to ensure the caramel evenly coats the bottom before solidifying. Set the ramekins aside.
Peel and place the banana in a large bowl. Using a fork or potato masher, mash the banana until quite smooth. Add the remaining sugar, yolks, eggs, salt, vanilla, and banana extract. Whisk to combine and set aside.
1 overripe banana, 3 large egg yolks, 2 large eggs, 1 tsp vanilla extract, 1 tsp banana extract, 1/2 tsp salt
Pour the milk and cream into a small saucepan. Add the turmeric and whisk to combine. Place over medium heat until on the verge of boiling.** Take the cream off of the heat and slowly ladle the mixture into the egg mixture while whisking constantly. This will temper the eggs.
2 cups whole milk, 1 cup heavy cream, 1 tsp ground turmeric
Pour the finished custard into a pitcher and divide it among the ramekins. Make sure you leave a little space at the top of each.
Pour recently boiling water into the roasting pan until the bottom half of the ramekins are immersed. Transfer the roasting pan to the oven and cook for 30-35 minutes until the custard is set but still is quite wobbly.
Take the roasting pan out of the oven and take the ramekins out of the water. Arrange them on a cooling rack and let them cool to room temperature before transferring them to the fridge and chilling them for at least 2 hours.
When ready to serve, carefully run a small palette or butter knife along the edges of the crème caramel and place a plate on top. Invert the ramekin on the plate and the caramel should release. Serve immediately.
Notes
** Do not let the mixture come to a boil at any point.