I'm thinking about making a Chocolate And Raspberry Pavlova for a dessert but I need to leave the house for a couple of hours and I will need to serve the pavlova quite soon after my return. If I make the pavlova before I leave would it be possible to leave the pavlova in the oven until I get back? My father said it would be best to turn off the oven when I go out but would it be possible to keep it in the oven with the oven switched off until I return?
The meringue base of a pavlova is usually made by baking the meringue in a moderate oven (around 180c/350F) for 45 minutes to 1 hour and then turning off the oven and leaving the meringue in the oven while it cools. This gives a crisp outer shell with a marshmallowy interior. Nigella's Chocolate Raspberry Pavlova (from Forever Summer) is made in a similar way, though the oven is turned down to 150c/300F as soon as the meringue is put in the oven and is cooked for 1 1/4 hours. However it is still left in the oven as it cools.
The cooling down period is important as this helps the pavlova to dry out a little more on the outside without browning, and also lets the centre set without drying out. Even if you bake the meringue at a lower temperature for a longer time then it still needs the cooling down period. So if you are planning to go out then you do need to follow your father's suggestion and do the baking part of the recipe before you go out, and then leave the oven off and the meringue in the oven cooling while you are out.
If you know that you need a dessert and have limited time on the day then you can make the meringue a day ahead and once it has cooled fully you can store it in an airtight container for a day, unless the weather is very humid. It is also worth considering Nigella's Forgotten Pudding (from Nigella Express) which can be made the night before and left overnight in a switched off oven.