Place 2-1/2 tablespoons oats, the flour, sugar and cinnamon in microwave-safe mug; stir to mix well.

Stir in banana and egg white until well blended, scraping sides and bottom of mug with rubber spatula.

Sprinkle with remaining 1-1/2 teaspoons oats.

Microwave on HIGH 80 to 90 seconds until risen and just firm to the touch.

Let stand 3 to 5 minutes before serving.