Preheat the oven to 415ºF/200ºC.
Slice the bananas lengthwise and peel.
Roll the puff pastry sheet out on a lightly floured piece of parchment paper until it grows 2 to 3 inches longer and wider.
Place the chocolate chips on top of the puff pastry dough, lengthwise. The pile of chocolate chips should be approximately 2 inches wide.
Place the banana slices on top of the chocolate with the curves all facing away from you.
Fold the top of the pastry dough over the bananas and chocolate, then fold the bottom of the dough down over that.
Bend the dough away from you into a circle, so the bananas inside the dough also form a circle.
Secure both ends by pinching the dough together. (Tip! You can use some of the milk to help the dough stick together easier.)
With a sharp knife, make 1 inch slits on the very top of the wreath 1 inch apart.
Using a pastry brush, lightly brush the top of the dough with milk, then cover with sprinkles.
Bake for 20-25 minutes, or until the pastry is golden brown.