Preheat oven to 350°. Lightly butter a 9-inch round cake pan, line the bottom and sides with parchment paper, and butter the parchment paper; set aside.
For cake: In a large bowl, toss together the cranberries, apples, brown sugar, cornstarch, and zest; set aside.
In another large bowl, whisk together the flour, cornmeal, baking powder, baking soda, salt, and granulated sugar; set aside. In a medium bowl, whisk together the buttermilk, eggs, vanilla, almond extract, and melted butter. Add the wet ingredients to the dry ingredients, and stir to combine with a rubber spatula or wooden spoon.
Pour the apple-cranberry mixture in the bottom of the prepared cake pan, and spread them out in an even layer, making sure the cranberries are evenly distributed all around. Pour the cake batter on top and smooth out. Bake until a wooden pick inserted in center comes out clean, 40 to 45 minutes. Cool in the pan for 15 minutes.
For cream topping: In a large bowl, beat cream, sugar, and vanilla with a mixer at medium speed until soft peaks form. Invert the cake on a cake stand or serving platter. Serve warm or at room temperature with fresh whipped cream, if desired.