In France, gâteau au yaourt is a cake that uses an entire container of yogurt then cleverly employs the empty container as the measuring cup for the flour, sugar and oil. It’s easy to throw together and a perfect recipe to make with children. If you’ve got a 4-ounce container of yogurt, bake the cake in a 9-by-5-inch loaf pan; if it’s a 5.3-ounce container, use a 9-inch round cake pan. Either way, the number of eggs and amounts of both baking powder and salt remain the same. The cake is very forgiving this way. It’s also a blank canvas, so feel free to flavor it to your liking with vanilla or other extracts, ground spices or grated citrus zest. Store leftovers in an airtight container at room temperature for up to three days.