Yes, it is generally okay to cool off a cake quickly in the refrigerator to speed up the process of adding frosting. However, there are some important considerations to keep in mind to ensure the best results:
Let the cake cool slightly: Before placing the cake in the refrigerator, let it cool on a wire rack at room temperature for about 10-15 minutes. This helps prevent condensation from forming on the cake's surface when it enters the refrigerator.
Cover the cake: To avoid the cake from drying out in the refrigerator, cover it loosely with plastic wrap or place it in an airtight container.
Don't overcrowd the refrigerator: If you have other items in the refrigerator, try to leave enough space around the cake to allow proper air circulation. This helps maintain a consistent and even cooling process.
Use a chilled frosting: While the cake is cooling in the refrigerator, you can prepare the frosting. Using chilled frosting can help prevent it from melting or becoming too runny when you apply it to the cake.
Avoid overcooling: Don't leave the cake in the refrigerator for an extended period. Once it has cooled sufficiently, take it out and apply the frosting promptly. Overcooling may affect the texture and flavor of the cake.
Remember that while refrigerating can expedite the cooling process, it might not be suitable for all types of cakes. Delicate and airy cakes, such as angel food cakes, might not respond well to refrigeration. Also, if you have a custard-based filling or frosting, like whipped cream or mousse, it's best to keep the cake refrigerated until serving time.
In general, cooling a cake in the refrigerator briefly to apply frosting is a common practice, but make sure to handle the cake gently and avoid any drastic temperature changes to maintain its quality.