Preheat oven to 350 degrees F.
Butter and flour an 8-inch round cake pan.
In a medium bowl, whisk together the cornmeal, cake flour and baking powder. Using a stand mixer with a paddle attachment, beat the butter and almond paste on high speed until smooth, about 3 minutes. Reduce speed to low and add vanilla extract and slowly pour in confectioners' sugar. Mix until light and fluffy, about 3 minutes. Raise speed to high and add the egg yolks and whole eggs, one at a time. Reduce speed to medium and add the sour cream and dry ingredients and mix until just incorporated.
Pour the batter into the prepared cake pan and smooth the surface with a spatula. Bake in the lower third of the oven for 35 minutes, or until the cake is golden and pulls away from the sides of the pan. Transfer pan to a wire rack and let cool. Remove from pan and dust with confectioners' sugar.