Maa Skandmata is worshipped on the fifth day of Navratri. She is the mother of Lord Ganesha and Lord Kartikeya. The mantra for offering prayers to maa Skandamata can be found here and her favourite prasad is banana.

The mother of lord Kartikeya,
      you signify compassion and love;
you empower your devotees,
      bless them from the heavens above. 

You instill confidence in them,
      dismiss the clouds of self-doubt;
like the Sun drives away darkness,
      and clarity of purpose sprout. 

Bless us oh revered mother,
      that we keep our values intact;
through the storm of uncertainty, 
      your divine blessings, we always attract. 
      

Have a blessed Navratri.