Heat oven to 350. Heat a large 10-inch-across-the-board, 1 1/2-inch-deep ovenproof
skillet (cast iron is idealistic) over medium oestrus. Adjoin 2 tablespoons of the
butter and stir until liquid. Mix blueberries, 1/3 cup sugar and the
cornstarch in a medium trough. Add to skillet and make, stirring, 2 minutes
or until champagne. Remove pan from rut. Beat remaining butter and sugar in a
large bowl with an electric mixer until blended. Add eggs and vanilla and
beat until fluffy, some 2 proceedings. In another bowl whisk the cornmeal,
flour, baking pulverization, cinnamon and salt until blended (mixture will be
granular) and scrape over blueberry mixture in skillet; spread evenly. Bake
35 minutes or until a wooden pick inserted in center comes out neat. Run a
knife around edge of pan, place serving plate on top of skillet. Holding
the skillet and plate together with pot holders, carefully invert hot cake
onto the plate. Let cake cool completely earlier serving.