Preheat the oven to 350 degrees. Butter a 9-inch loaf pan.
To prepare the cake: In the bowl of an electric mixer fitted with paddle attachment, combine the sugar, flour, and baking powder on the lowest speed. Add the eggs and continue mixing until the mixture forms a smooth paste. Mix in the crème fraiche, lemon juice, lemon zest, and melted butter. Pour the batter into the buttered loaf pan and transfer to the center rack of the oven.
Bake for 60 to 65 minutes or until a toothpick inserted into the center of the cake comes out clean. Let the cake cool in the pan for 5 to 10 minutes, then turn it out onto a rack to cool.
To prepare the glaze: In a bowl, mix the powdered sugar and lemon juice until the sugar dissolves. Brush the top of the cake with the glaze while the cake is still warm.