I recently made the Nigella Mini Pavlovas recipe. They looked great until I topped them with cream and fruit at which point they caved in like a volcano. The problem was that the shell was wafer thin and there was a large air pocket between it and the marshmallow inside. What did I do wrong? Thanks!
Nigella's Mini Pavlovas (from HOW TO BE A DOMESTIC GODDESS) are smaller, individual versions of pavlova meringues. Pavlova meringues have a softer interior than a regular meringue and sometimes larger pavlova meringues sink back and crack slightly on cooling, so it is not unusual to have a little air inside the meringue. It is less likely that the egg whites were whisked incorrectly, but if you piled spoonfuls of meringue on top of each other then some air could have been trapped inside so try to use single, large heaped spoonfuls and then use the back of a small spoon to push down slightly and make a shallow indentation in the top of the meringue.
However if the shell was very fragile this could be caused by a couple of factors. One is that it was not quite cooked properly so check that the oven is not too cool. Also some fan ovens cool very quickly by continuing to run the fan after the oven has been turned off. If you have one of these ovens then you may need to bake the meringues for the first 30 minutes then turn the oven on the lowest possible heat for another 10-15 minutes before turing the oven off and leaving for a further 20 minutes. If you need to do this, keep an eye on the meringues to check that they are not colouring too much. Also it is difficult to make and store meringues in humid or wet weather, so if you made the meringues in one of these conditions then it is possible that the shell of the meringue did not set properly or softened once it came out of the oven.