Preheat oven to 350 F.
Oil and add a parchment round to four, 4-inch cake pans.
Crumb topping: Stir together ingredients and refrigerate until ready to use.
Cake: Combine the flour, sugar, baking powder and salt, set aside.
Mix together the greek yogurt, oil, eggs, lemon juice and lemon zest.
Add the wet ingredients to the dry and stir to combine.
Evenly distribute the batter between the prepared cake pans.
Top them with the crumb topping.
Bake for 25-30 minutes, until toothpick inserted in center comes out clean.
Cool completely.
Icing: Mix together the powdered sugar and lemon juice.
Drizzle over cool cakes.
Enjoy!
