A brace from Roberts, plus a header from Ryan Nelsen, had Allardyce purring after the 3-1 win.
"The first goal was probably more pleasurable for me because of the way he took it," Allardyce told Radio Rovers.
"As a goal with the build-up and the finish probably everyone will look at his second and say that was the better goal, but the way he took the first one for me, rolling the defender and the quick flick before the anybody can move, that is what you want to see from a front man.
"The second goal is obviously a beautiful looking goal but the first was a better striker's goal for me.
"We've been waiting for that for a while for Jason, he's been out of the side because he hasn't played as well as he had been at the start of the season.
"But he's come back with a vengeance and two goals in 45 minutes is what we are looking for."