Preheat oven to 170°C. Grease and flour 15 mini muffin tins or mini tart pans.
Whisk eggs briskly with sugar. Add yogurt, oil, and lemon zest and whisk briskly until fully combined. Add in flour, baking powder, and salt, and stir until the batter comes together.
Portion the batter out evenly into the prepared tins and press two or three blueberries into the top. Bake for 12-15 minutes, until the edges are golden and the blueberries have released their juices.
Allow to cool completely, then sprinkle with powdered sugar.