It's a recipe for Gateau au Yaourt (yogurt cake)! It's a cake whose ingredients are measured in multiples of the volume of the yogurt pot (125mL pot used). I love how they've stapled the packets of baking powder and vanilla sugar to the instructions. I think I need to visit a French supermarket!

Clotilde made one recently with raspberries but I think mine shall be plain and simple. And uh...maybe made with melted butter.