Preheat your oven to 180°C and prepare your cake tin by greasing it with butter and lining it with parchment paper. This will prevent the cake from sticking to the tin.

In a large mixing bowl, cream the butter and sugar together until light and fluffy. Add the eggs one at a time, mixing well after each addition. Then, add the ground almonds, orange zest, vanilla extract, baking powder, and salt. Mix everything together until well combined.

Pour the cake batter into the prepared tin and smooth out the surface with a spatula. Bake the cake in the preheated oven for around 40-45 minutes, or until a toothpick inserted into the center of the cake comes out clean.

Once the cake is done, remove it from the oven and let it cool in the tin for around 10-15 minutes. Then, carefully remove it from the tin and transfer it to a wire rack to cool completely.