Orangette (can't get to her site anymore, so reposting here)
This type of cake is an old classic in France, so simple kids can make it. It is also very forgiving, so even Olivia can help and over/under fill and still will taste great. Traditionally, the ingredients are measured in a yogurt jar, a small glass cylinder that holds about 125 ml. Because most American yogurts don't come in such smart packaging, you'll want to know that 1 jar equals about 1/2 cup.
For the cake:
1 jar plain yogurt
2 jars granulated sugar
3 large eggs
3 jars unbleached all-purpose flour
2 tsp. baking powder
2 tsp. grated lemon zest
1 jar canola oil
For the glaze:
Juice from 2 lemons
1/2 jar powdered sugar
Preheat the oven to 350 degrees Fahrenheit.
In a large bowl, combine the yogurt, sugar, and eggs, stirring until well blended. Add the flour, baking powder, and zest, mixing to just combine. Add the oil and stir to incorporate. Pour and scrape the batter into a greased 9-inch round cake pan.
Bake for 30-35 minutes, until the cake feels springy to the touch and a toothpick inserted into the center comes out clean. Do not overbake.
Cool cake on a rack for about 20 minutes; then turn it out of the pan to cool completely.
When the cake is thoroughly cooled, combine the lemon juice and powdered sugar in a small bowl and spoon it gently over the cake. The glaze will be thin and will soak in like a syrup.