Heat the oven to 350F. Coat 24 large muffin cups with nonstick baking spray or butter.
Sift together the flour, baking powder and salt in a medium bowl.
In the bowl of a stand mixer fitted with the paddle attachment (or in a large bowl, using a handheld mixer), cream the butter and sugar on medium speed until light and fluffy, about 3 minutes.
Mix the creme fraiche, eggs, lemon zest, and juice together in a small bowl with a fork or small whisk. With the mixer on medium speed, alternately add the dry and wet ingredients in batches and continue beating until the batter is smooth, occasionally scraping down the sides of the bowl, about 3 minutes.
Using a large ice cream scoop or a large spoon, scoop approximately 1/2 cup batter into each prepared muffin cup. Bake for 18 minutes, or until the tops of the cakes appear matte and the shiny center has disappeared; do not bake until the cakes turn golden. Let the cakes cool in the pans for 5 minutes before removing them. Cool the cakes completely on a cooling rack before glazing, about 1 hour.
Sift the powdered sugar into a medium bowl. Add the lemon juice and pomegranate juice and stir with a small spatula until completely smooth. Let the glaze sit at room temperature for 10 minutes before using.