How do you keep profiteroles crisp?

To keep profiteroles crisp, you can try the following: once you have baked the cream puffs, split them in half and remove any damp pastry from the centre with a teaspoon. You can then return the pastry shells to a low oven for 5 minutes so that they have completely dried out. Store the puffs in an airtight container for up to 2 days and re-crisp them in a low oven for 5 minutes on the day you intend to use them. For the filling, use a creme patissiere rather than just whipped cream. Fill the bottom half of the cream puffs and then just add the tops at the last minute, which should keep the tops crisp.