If desired, sprinkle the mini marshmallows on top of the filling. This will add a touch of sweetness and a nice texture.
Bake:

Bake for 25 to 30 minutes, or until the top is golden brown and the filling is bubbling slightly around the edges. Be careful not to overbake, as the filling should remain moist.
Cooling:

Cool the bars in the pan for about 15 minutes, then transfer them to the refrigerator for at least 2 hours to firm up. This will make cutting easier.
Cutting and Serving:

Once cooled, remove the bars from the pan using the parchment paper. Cut into squares or rectangles, whichever you prefer.
Tips:
For an extra touch, you can add a pinch of fleur de sel on top after baking.
These bars will keep well in an airtight container in the refrigerator for about a week.
Enjoy these delicious Ooey Gooey Bars, perfect for a treat or a dessert to share! If you have any further questions or need clarification, please don’t hesitate to ask!