As other's have said, the pickings are slim, especially since Epcot is not opening until 11 right now. I did stop at Starbucks in MK last week because I was hungry and didn't want anything sweet but it's not an ideal solution. There almost always is a line there, I don't drink Starbucks coffee but I needed a breakfast sandwich. Most of the restaurants around both parks have breakfast. I love the breakfast at Fresh Med. Cafe at the Dolphin and you can get a fairly decent on at Picabus there as well. Neither are open every day of the week so you have to check their website to find out which one is available which day.
During normal times, you can get breakfast at Sunshine Grill at Epcot and the bakery in France opens at park opening as well.