Meyer Lemon-Polenta Upside Down Cake

Meyer lemons are in season  and this cake is the perfect way to make them shine!    The Meyer lemon is a cross between a true lemon and a mandarin orange. It is thinner and smoother skinned with a distinctive taste.  In this cake, thinly-sliced Meyer lemon slices (use a mandoline) are arranged in a concentric pattern in a caramel base.  The zest of 2 more Meyer lemons goes into the batter to add another layer of citrus flavor. The cake, inspired by a polenta cake from pastry chef Hannah Buoye of A16 Rockridge in Oakland, CA, is a dense, moist dessert as pretty as it is delicious.  It has a really nice crumb and a bit of a crunch from the cornmeal.  As the lemon slices bake, they absorb the butter and the brown sugar from  the caramel base and turn into a marmalade-like consistency and taste.   If you are a lemon lover, this cake is for you!  The caramelized lemon slices will require a serrated knife to cut into.  Let the cake cool 2 hours before taking it out of the pan.