This is a topic that's probably better suited for the Midwest section of the Travel & Dining forum, but I'll shoot off an idea here.

Why not take the Hiawatha Light Rail line up to downtown Minneapolis and have breakfast at a place like Hell's Kitchen. I've never been there, but I've heard rave reviews of the place. It's maybe 4-5 blocks south of the light rail station at the Nicollet Mall (which, coincidentially, might be a nice place to take a stroll in the early morning before or after breakfast. You could take the light rail south to the Mall of America, but it doesn't open until 10am, so that wouldn't work for you.

Otherwise, if you don't want to go all the way downtown, there are going to be some nice cafes and other restaurants around most of the other stops heading toward downtown. If you like waterfalls/scenic views, get off at the 50th Street/Minnehaha Park stop and explore around there. With a little Googling, I'm sure you can find some things to do around there that would interest you.