Preheat the oven to 160°C.
Beat the butter, sugar, and lemon zest together for 3-4 minutes.
Add the eggs, two at a time, beating well after each addition.
Combine the sour cream and vanilla extract, then add to the mixture.
Sift in the self-raising flour, cake flour, baking powder, and salt. Mix until well combined.
Prepare a Bundt pan with spray and cook, using a pastry brush to grease all the indents.
Pour the batter into the prepared pan, nudging the batter into the pan indents with a spatula.
Bake for 60 minutes.
Allow to cool completely in the pan.