Preheat the oven to 350F (180C). Grease a 8 inch (20cm) pan and line with parchment paper.
In a medium bowl whisk together flour with baking powder, baking soda and salt.
In a large bowl mix oil with sugar until combined. Add yogurt, buttermilk, vanilla extract and vinegar. Mix to combine.
Gradually mix in flour mixture. Don’t overmix.
In a bowl toss the fruits with 1 tablespoon flour. Using a spatula, gently fold the fruits into the batter.
Pour the batter into the prepared pan.
Prepare crumb topping: In a medium bowl combine sugar with flour and oil.
Spread the crumbs on top of the cake.
Bake for about 50-60 minutes until golden brown and a toothpick inserted into the center comes out clean.
Cool the cake on a wire rack.
Dust with powdered sugar before serving. Enjoy!