Place the sugar and softened butter in the bowl of a stand mixer and beat together for approximately 7 minutes. It should be thick and pale yellow in colour.
Beat in the eggs one at a time, while beating well after each addition.
Stir in the lemon zest, vanilla and liqueur of your choice. (I used Amaretto liqueur). But you can use a liqueur of your choice.
Sift in the flour, cornmeal, ground hazelnut, baking powder and salt and mix until combiened. Any larger bits of ground hazelnuts that don't pass through the sieve can be stirred in.
Transfer the batter into a prepared, greased, and floured baking pan. (If you don't have the ridged baking pan, you can use a regular loaf pan.)
Bake in a preheated oven, 350 degrees F, for 35 to 40 minutes.
When ready, the cake should spring back when lightly touched. Or, check for doneness with a toothpick. If it comes out clean, then the cake is ready.
Allow the cake to cool in the baking pan for about 30 minutes before inverting the cake pan and releasing the cake.
Make sure the cake cools completely before cutting into it. This way it maintains its delicate structure and moist crumb. Then dust with powdered sugar before serving.
Enjoy with your favourite hot beverage.