Preheat oven to 350º F. In a mixing bowl, cream the butter and sugar until just combined. In a separate bowl, combine all the dry ingredients (almond flour, cornmeal, baking powder, salt).
Add the eggs to butter and sugar mixture one at a time, alternating with the flour mixture, mixing briefly after each addition to incorporate. Add the vanilla and lemon zest and stir to combine.
Prepare an 8- or 9-inch round cake pan with cooking spray and a piece of parchment paper cut to size.
Line the bottom of the pan with the fruit in an even layer. Top with batter, filling about ¾ of the way to the top of the pan.
Bake for 40-50 minutes or until firm in center and golden in color. Remove from the oven and let the cake rest for 5-10 minutes before inverting onto a plate. Do this by placing a plate larger than the baking pan on top of the cake pan and then flipping to invert.
Once inverted, take the parchment off and reveal a beautiful layer of fruit. Serve warm with ice cream or whipped cream. It is also great for breakfast at room temperature the next day.