Combine strawberries and 3 tbsp sugar and set aside.
Preheat oven to 350F,lightly spray an 8 inch round cake pan..in bowl stir together flour, cornmeal, 1/3 cup sugar , zest, baking powder, baking soda,using a pastry blender or your fingers work butter into flour mixture, until crumbly..Make well in centre and pou in buttermilk, stir until dry ingredients are moistened...do not over-mix as shortcake will be tough. Transfer dough into pan, pat down gently , flatten and brush with 1 tbsp cream.
Bake in center of oven until top is golden and cake tester inserted into center comes outclean about 28 to 30 minutes...remove cake cool on wire rack for 10 minutes and remove cake from pan to cool. Beat remaining cream with remaining sugar in large bowl until stiff peaks form...
Assemble by cutting cake in half horizontally..set bottom on platter scatter half the strawberries on top and spread 1/2 cream mix on top of berries add other half of cake on topaand press down gently,,add remaining berries and cream on top of cake...refrigerate any left-over cake.