Make the cake layer: Preheat the oven to 350 Fahrenheits. Add flour, sugar, baking powder, egg yolks, canola oil, and milk in a medium bowl. Mix until well combined. Grease the 8 x 8 pan with butter. Pour the cake mixture into the pan. Bake for 20 minutes or until golden on top, and the wooden skewer is mostly dry after you poke the cake. Remove from the oven and leave on the counter.
Make the meringue: In a mixer bowl, add egg whites and start mixing at low speed. At the same time, in a small pot, add sugar, water, and a squeeze of fresh lemon juice. Mix until well combined. Bring to boil and boil for one more minute. Remove from the heat. Start adding sugar and lemon juice mixture to the egg whites, one tablespoon at a time, while the mixer is still on low speed. Keep adding the sugar and lemon juice mixture (while increasing the mixer speed slightly) until the soft peaks are formed. Keep beating the meringue at high speed until you get the desired texture. The meringue should have stiff peaks when you hold the mixer head up.
Spread the meringue to the edges of the pan with the cake layer. Put in the fridge for 2 hours before serving. Grate the chocolate or walnuts on top. Enjoy!
Notes
When separating the egg white from the egg yolk, ensure that there is not a single drop of egg yolk in the egg whites.
For this recipe, I used my KitchenAid mixer. When beating the egg whites, I started with speed one, then speed two. Then, when I started adding sugar and lemon juice mixture, I increased the speed slightly. Once I added the whole mixture to the egg whites, I increased the speed to high (speed eight and then speed ten for the last minute or two).