Preheat your oven to 350°F (175°C). Grease a 9-inch round cake pan and line the bottom with parchment paper. Lightly flour the sides to prevent sticking.

In a large mixing bowl, cream the softened butter with the superfine sugar using an electric mixer on medium speed until the mixture is pale and fluffy. This should take about 3-4 minutes.

Gradually add the lightly beaten eggs to the butter-sugar mixture, beating well after each addition. Stir in the vanilla extract. If the mixture looks slightly curdled, that’s normal and will smooth out with the addition of dry ingredients.

In a separate bowl, sift together the cake flour, baking powder, baking soda, and salt. Add the ground toasted almonds to this dry mixture and stir to combine. Add the dry mixture to the creamed mixture in three parts, alternating with the sour cream (start and end with the dry ingredients). Mix just until combined do not over mix.

Pour the batter into the prepared cake pan and smooth the top with a spatula. Tap the pan lightly on the counter to release any air bubbles. Bake in the preheated oven for 28–32 minutes, or until a toothpick inserted in the center comes out clean.

Let the cake cool in the pan for 10 minutes, then run a knife around the edges and invert it onto a wire rack to cool completely. Once cool, you can dust it with powdered sugar, glaze it, or serve it plain with tea or coffee.