Preheat the oven to 350°F (180°C). Grease an 8-inch (20 cm) round cake pan and line the bottom with parchment paper.
Mix the flour with baking powder and salt. Set aside.
In a large bowl add the eggs, sugar, vanilla extract and lemon zest.
Whisk until slightly pale and well combined.
Add the oil and mix to combine.
Add the Greek yogurt. Whisk until smooth.
Add the flour mixture and gently mix just until combined.
Do not overmix.
Cut the peaches into slices and place them in a bowl with the blueberries.
Toss the peaches and blueberries with 1 tablespoon of flour.
Gently fold the floured peaches and blueberries into the batter.
Distribute them evenly without crushing the blueberries.
Transfer the batter to the prepared pan and smooth the top.
Arrange peach slices and blueberries over the surface, gently pressing the peach pieces slightly into the batter. Sprinkle the peaches with 1 tablespoon sugar.
Bake for 45–55 minutes, or until golden and a toothpick inserted into the center comes out clean or with a few moist crumbs. If the top browns too quickly, loosely cover with foil during the last 10–15 minutes.
Let the cake cool in the pan for about 15 minutes, then transfer it to a wire rack to cool completely before slicing.
Dust the cake with powdered sugar before serving.