I'm making oatmeal cookies and I have no brown sugar only white sugar.
sorry this answer is a bit late, but for next time, brown sugar is basically just white sugar with molasses, so if you have some molasses just use white sugar instead of the brown and add molasses. :)
you would use white sugar. brown sugar is a little bit sweeter that white. or you could just go buy some brown sugar. you pick.
I think sugar is sugar, brown is slightly sweeter, try with the normal stuff
maybe molasses? not sure how much you would use though.