Preheat the oven to 180C/350 C, grease two 8"/20cm round cake pans and line with parchment paper, set aside.
In the bowl of a stand mixer cream softened butter with sugar until light and fluffy.
Start adding eggs one by one, whipping until well combined after each addition for about a minute. Add vanilla bean paste and lemon zest.
Combine sifted flour, baking soda and powder and salt in a separate bowl. Add the dry ingredients to the wet ingredients and mix well, stopping the mixer and scraping sides and the bottom of the bowl.
Divide the batter between two pans. Weigh them to get exactly the same cake in size. Bake in the oven for 30-35 minutes or until cake tester comes out clean.
Remove from the oven and set on a wire rack to cool for 20 minutes, then remove from the pan and cool completely.