Preheat oven to 325 degrees F. Whisk together first five ingredients until smooth. Stir in cornmeal and mix until well-combined. Pour mixtureÐwhich will appear quite thin - into a tight-sealing, lightly greased, 9-10 inch spring-form cake pan. Disperse the pieces of butter over the top.
Bake 60-70 minutes, or until cake begins to turn golden-brown on the edges and begins to firm up. Let cake set 10 minutes, and then unmould. When still warm, cut into wedges and top each with slices of pear, a spoon of whipped cream, a dusting of icing sugar, and a spring of mint.