Preheat your oven to 350°F. Prepare 2 9-inch round baking dishes by lining the bottoms with parchment paper. There’s no need to grease the sides. I like to use a springform pan for ease.
In the stand of an electric mixer, beat the eggs with the whisk attachment on high speed for 1 minute, or until foamy.
Slowly add the 1 cup of sugar while the mixer continues whisking.
Whip your eggs and sugar for 10-15 minutes (this is the most important step!) until fluffy. To test to make sure it is done whipping, let a thick ribbon of the mixture fall in a “figure 8” on top of the mixture. If it disappears immediately into the mixture, keep whipping. If it remains then you’re ready to move on.
In a medium bowl, whisk together the 1 cup of flour and 1 teaspoon baking powder.
Add the flour mixture to the egg mixture ¼ cup at a time. Fold the flour into the eggs until just combined. Be sure to scrape the bottom of the bowl to ensure there is no flour stuck to the bottom of the bowl.
Do not overmix or your cake will fall when baked. You want to keep the air in the fluffy eggs, so fold the flour in until you don’t see any streaks in the batter and then stop.
Pour the cake batter into the two prepared pans. Bake for 25 minutes, or until the cakes are golden brown on top.
Remove cakes by releasing the sides by sliding a butter knife around the outside of the cake. Then, turn the cakes over onto a cooling rack to fully cool.