Both Angela's Ashes and A Tree Grows in Brooklyn are framed as a bildungsroman, or coming of age story.  The reader witnesses Frank and Francie building their characters against the backdrop of their families' hardship.  Frank in Ireland has to deal with poverty continually knocking on his family's door and a drunk father who squanders away his earnings rather than help contribute to the care of his family.  Similarly, Francie's mother does all she can to get work to support her children while Johnny is often found at the local bar.  Despite this, Frank and Francie are not bitter towards their fathers, and although they recognize that their fathers are not behaving properly, the children still love them and see some good in them.  As these stories come to a close, Frank and Francie both want to pursue a life away from their neighborhoods to see what life is like on the outside of their limited communities.  So Angela's Ashes and A Tree Grows in Brooklyn have much in common.