Combine active starter and water in a bowl and whisk well.
Add flour, vanilla, and salt to the starter and water and mix well. Use a spatula or slightly damp hands to form a rough ball of dough.
Cover the dough with saran wrap or a tea towel and let rest for 45-60 minutes.
Add in chocolate chips and perform first set of stretch and folds. To do stretch and folds lift up one side of the dough and fold it back over the other side of the dough. Continue to stretch and fold until the dough forms a smooth ball.
Perform 3 additional sets of stretch and folds, spaced 20-30 minutes apart. Cover the dough in between each set.
Cover the dough and let it bulk rise. The bulk rise will depend on temperature, about 8-10 hours at 72 degrees.
After the bulk rise, shape the dough: lay the dough on a floured work surface and fold the four sides inward to form a ball. Gently cup the dough and rotate it counterclockwise to create surface tension.
Set the dough in a banneton or a floured bowl and cover it. Then place in the fridge for at least one hour.
Optional: prior to baking freeze the dough for 30 minutes in order to improve the score.
When you are ready to bake, preheat the oven to 450 degrees. Score the dough, set it on a piece of parchment paper, and place it in a cold Dutch oven.
Bake the bread for 25 minutes, then carefully remove the lid of the Dutch oven. Bake for an additional 20-25 minutes or until the crust is golden brown.
Let the bread cool for one hour before slicing. Enjoy!