River Belle is located on the edge of Adventureland, Frontierland, and New Orleans Square...but right now it's closed for refurbishment and not due to reopen until mid-December. You can get a Mickey Mouse waffle at Carnation Cafe on Main Street...
It looks like Cafe Orleans (next to French Market), will be serving breakfast while the River Belle is closed. You can check to see if they will be serving Mickey Mouse pancakes.
Otherwise, I am also bummed as it is one of my favorite traditions of having breakfast and Mickey Mouse Pancakes at the River Belle whenever we go.
No where I know besides the River Belle Terrace serves Mickey Mouse pancakes. However, many locations including Carnation Cafe do serve Mickey Mouse waffles.