Using l tablespoon of the butter, grease a 1 1/2-quart microwaveable round baking dish or bowl and sprinkle with the 1 tablespoon sugar; set aside.

In a large microwaveable dish, toss 2 cups blueberries and the remaining 3/4 cup sugar. Cover loosely with clear plastic wrap and microwave on HIGH (100 % POWER)* until blueberries are tender, about 4 minutes.

In the container of a food processor, combine cooked blueberries, flour, yogurt, vanilla and the remaining 4 tablespoons butter; process until smooth. Add eggs; pulse to blend.

Pour mixture into the reserved buttered dish; stir in remaining 2 cups blueberries. Cover dish loosely with plastic wrap; microwave on HIGH until set in the center, 12 to 14 minutes. Prick plastic wrap to release steam; cover dish with a large plate and let stand 20 to 30 minutes. Uncover and remove plastic wrap; invert pudding onto a serving plate.

Serve warm with additional vanilla yogurt, if desired.

*Note: Tested in a 625 watt microwave oven