Preheat oven to 400°F. Take one phyllo sheet, brush well with butter, sprinkle with sugar. Place another phyllo on top and repeat until you have 4 sheets stacked on top. Slice bananas in quarters and place 1 piece of chocolate between 2 pieces of banana. Put banana/chocolate in the middle end section and roll up, tucking in the sides. Brush top of strudel with butter and sprinkle with sugar. Bake for 15 minutes.