As a rule, a CTE will NEVER improve performance. A CTE is essentially a disposable view. There are no additional statistics stored, no indexes, etc. It functions as a shorthand for a subquery. In my opinion they can be EASILY overused (I see a lot of overuse in code in my job).
Check the cupcakes at the minimum baking time. If the recommended baking time is 18-22 minutes, check them at 17 or 18 minutes (just a quick peek, make sure not to let too much heat out of the oven). If the tops are rounded and no long appear wet, they may be done.
Generally, they're baked in a 350Â°F oven for 10 to 15 minutes. Jumbo cupcakes: A recipe that makes 24 standard (2-1/2-inch) cupcakes will make 10 to 16 jumbo cupcakes. Typically, they're baked in a 350Â°F oven for about 25 minutes. Test the doneness of cupcakes by inserting a wooden toothpick into the centers.