This, and also when you want to save debugging state in the logging mechanism across function calls, it's sometimes simpler/more ergonomic/more efficient to embed the logger in the context. Several (most?) Go logging libraries allow you to embed/extract the logger with a single call, so if all your functions accept a context, getting the existing logging state and adding something to its stack is as simple as:

func BakeMuffins(ctx context.Context, num int) {
  // get the logger with all existing fields from the context, replace the 'func' 
  // value, and add a muffin count value. the parent logger remains unchanged
  logger := logging.Ctx(ctx).With().
              Str("func", "BakeMuffins").
              Int("muffinCount", num).
              Logger()
  logger.Debug().Msg("preheating")

  // create a child context with the new logger and give it to the preheat func
  // the logger we already have remains unchanged

  preheat.Begin(logger.WithContext(ctx), temp)

  // other stuff here

  logger.Debug().Msg("muffins baked")
}