Heat oven to 175 C. Line a 20 cm round pan with parchment and lightly grease the sides.
Toss blueberries with 1 tbsp flour and set aside.
Whisk yogurt sugar eggs oil vanilla and lemon zest until smooth.
Sift flour baking powder and salt over the bowl and fold just until combined.
Fold in most of the blueberries. Spread batter in the pan then scatter the rest on top.
Bake 35 to 45 minutes until the top springs back and a tester comes out with a few moist crumbs.
Cool 15 minutes in the pan. Lift out to a rack. Dust with powdered sugar. Slice and serve.