creme fraiche from scratch. It takes 12-24 hours to be done, so make it before you make the cake. This cake really asks for something less sweet and more tart as a topping and the creme friache complemented it perfectly. Creme fraiche has a similar taste to sour cream but it's more creamy and less tart. This was my first time trying it and I really liked it. The recipe for the yogurt cake was from Mint Design Blog. Have fun making this, it's delicious. xo,Yana.