Instead of Aala ala matwala barfi, it goes aala ala bada aala barfi. And hence, the meaning of Aala is different here. Here, aala is Urdu and means great, 'top quality' or top-notch.
However, aala is also a Marathi word, meaning 'has come', and is used as slang in Hindi too. So you can take the line as 'Barfi is great, very great', or 'great barfi is here.' However, the difference is not too much between both of them.