Preheat your oven to 325°F / 165°C. Generously grease a 9x5-inch loaf pan with butter.
In a medium bowl, whisk together the flour, cornmeal, baking powder, and salt.
Set aside.
In a large bowl using an electric mixer, cream the 2 sticks of softened butter until smooth.
Add 3/4 cup (960 ml) of the sugar and beat on medium-high speed until the mixture is light, fluffy, and pale in color, scraping down the sides of the bowl as needed.
Beat in the egg yolks one at a time, ensuring each is fully incorporated before adding the next.
Stir in the vanilla extract until just blended.
Gently mix the dry into the wet by hand with a spatula until just combined.
Do not overmix.
In a separate, clean bowl, beat the egg whites with an electric mixer until they become foamy. Gradually sprinkle in the remaining 1/4 cup (960 ml) of sugar while continuing to beat until soft peaks form.
Gently fold the whipped egg whites into the thick batter in two or three additions until no white streaks remain. Be careful not to deflate the mixture.
Pour the batter into the prepared loaf pan and smooth the top.
Bake for about 1 hour and 15 minutes, or until a toothpick inserted into the center comes out clean.
Let the cake cool in the pan for 5 minutes before inverting it onto a wire rack.
Remove the pan and turn the cake right side up to cool completely before slicing and serving.
After adding the flour mixture, mix only until just combined. Overmixing develops gluten and will make the pound cake tough.
Fold the egg whites in gently but thoroughly. This is the key to the cake's light, airy texture, so you don't want to knock the air out.
