I love making this in ramekins - it makes a tasty AND pretty dessert for guests.
Heat oven to 375°F.
Grease the sides and bottom of four ramekins with butter and dust with 1 T of the sugar.
Whisk remaining butter and sugar together, then add eggs, beating till fluffy. Add milk.
Stir in flour, baking powder and zest.
Cover the base of the ramekin with blueberries, generously, if desired.
Divide the batter between the ramekins.
Bake for 25-30 minutes or till the top is golden brown.
Serve with ice cream or cream or custard.