Light and puffy eclairs might take several hours to make, but you can make them in advance and freeze them for later use. Like cream puffs, eclairs are made with choux pastry, but are filled with pastry cream and topped with rich chocolate ganache. The chocolate topping can freeze together unless the eclairs are frozen separately before packaging. Eclairs can be frozen for up to two months and require only about 10 minutes to thaw before serving. As the custard filling thaws, the choux pastry softens so the entire eclair melts in your mouth.
Line a baking sheet with wax paper. Place the eclairs on the baking sheet with about 1 inch of spacing between each piece.
Place the tray in the freezer for about 1 hour or until the outside, particularly the chocolate topping, feels completely frozen.
Put the eclairs in a freezer bag, leaving about 1 inch of head space at the top of the bag. Squeeze out as much air as possible and seal the bag closed. Alternatively, store them in a freezer-safe storage container.
Label the package clearly with the date of packaging and the date of expiration, 1 to 2 months after the packaging date. Place the eclairs along the freezer walls for the first 24 hours to ensure they freeze solid quickly. Move them anywhere in the freezer after the initial freezing period.
If you prefer to retain the hardness of the outer pastry shell, it's best to freeze only the baked shells, adding the filling and topping only after the choux pastry has thawed completely. Serve immediately after applying the filling and topping so the pastry doesn't become soggy. When you freeze eclair shells without the chocolate topping, there's no need to place them in the freezer on a baking sheet. You can simply package them, label the package and place it in the freezer.
Eclair is also an alternative name for a Long John doughnut. It features pastry filling and chocolate topping on a long doughnut. While these are different than the choux pastry eclair, they can be frozen in the same way.