How far ahead can I make the filling and assemble the cupcakes?

Chill the cookie-dough filling until firm and it can be made 1-2 days ahead in the refrigerator. Filled and frosted cupcakes can be refrigerated for up to 3 days; bring to room temperature for 20–30 minutes before serving for best texture.

Can I freeze these cupcakes?

Yes—freeze un-frosted filled cupcakes in a single layer until solid, then wrap airtight and store up to 1 month. Thaw overnight in the refrigerator and frost just before serving. Fully frosted cupcakes can also be frozen, but texture and frosting appearance may shift slightly after thawing.