1. Melt butter in a large, microwave-safe mug, approx 1 minute. 2. Add brown sugar and water to mug, and stir vigorously until it forms a mixture. Add vanilla and stir in. 3. Gradually stir in flour, one tablespoon at a time, until mixture forms a batter. Add in salt and baking powder and stir until well-blended. 4. Add chocolate chips to top of mixture, and stir gently. Your chips should remain towards the top of batter. 5. Microwave mug with batter for 1 minute. If top of blondie is very liquidy and uncooked, return to microwave and cook for additional 10 seconds. Repeat again if still not cooked enough. Blondie should be moist and tacky, but solid. 6. Serve warm with ice cream or whipped cream. Makes 1 serving.