HEAT oven to 350° F.
PLACE four slices of raisin bread in a single layer in a buttered 9-inch square baking dish. TOP with bananas and four slices of raisin bread.
BLEND milk, cream cheese, eggs, sugar, flour and vanilla in a blender or food processor until smooth.
POUR over raisin bread. Let stand 5 minutes or refrigerate overnight.
BAKE 40 to 45 minutes (50 to 55 minutes if refrigerated) until set and top is toasted.
Let stand 10 minutes.
CUT French toast into diagonal halves and remove with spatula. Dust servings with powdered sugar if desired.