Preheat the oven to 340°F (170°C). Grease and line the bottom of a round cake pan with parchment paper.
Sift the cake flour and cornstarch together into a bowl. Set aside.
Add the softened butter and powdered sugar to a large mixing bowl. Beat with an electric mixer until pale, light, and fluffy.
Add the egg yolks one at a time, beating well after each addition. Scrape down the sides of the bowl as needed.
In a separate clean bowl, beat the egg whites until foamy. Gradually add the superfine sugar while continuing to beat. Whip until the meringue forms soft, glossy peaks.
Fold one-third of the meringue into the butter and egg yolk mixture to lighten it.
Gently fold in the remaining meringue, alternating with the sifted dry ingredients. Add the flour mixture a little at a time and fold just until combined.
Add the grated cheddar cheese and gently fold it into the batter. Avoid overmixing, as this can deflate the meringue and make the cake dense.
Pour the batter into the prepared cake pan and smooth the top. Sprinkle sliced almonds evenly over the batter.
Bake for about 50 minutes, or until the cake is golden and a toothpick inserted into the center comes out clean.
Let the cake cool in the pan for 15 minutes. Carefully remove it from the pan and transfer it to a wire rack to cool completely before slicing.
