You can make the brownies in advance and freeze the batter in a pan. Simple cover with lid or foil to seal. Add extra time when baking, or set out to defrost a couple of hours prior to baking. You can also divide the batter into 2-8×8 pans. Bake one and freeze the other. If you do this, put the ingredients for the caramel layer and chocolate drizzle in half. If you use a glass dish, make sure you defrost prior to baking, or put in the oven as it pre-heats. If you put a glass dish in a hot oven, it could shatter.