RTCLib parsing

Thanks Nick. So I've used sprintf, but am unclear how to get the last character.
This is what I have so far. How do I get the last character out ?

int parseMinutes()
{
 DateTime now = RTC.now();
  char buffer [10];
  int n; 
  int a =now.minute();
  n =sprintf (buffer, "%d", a);
  Serial.print("Buffer = ");
  Serial.print(buffer);  
  int len = strlen(buffer);
  Serial.print(" length = ");
  Serial.println(len); 
}

Results for say 9:15 are -

Buffer = 15 length = 2