Line the base and sides of 2x20cm/8inch round tins and preheat oven to 160C/320F/gas 3. Sift the flour, baking powder and salt in a large bowl and make a well in the centre and set aside. In a jug place the buttermilk, lemon juice and vanilla together and whisk.

Beat the zest, butter and sugar until light and fluffy, around 5 minutes. Add the eggs one at a time and beat until well combined. Gradually add the egg mixture to the bowl of flour alternating with the buttermilk mixture and fold in until there are no lumps.

Divide the mixture in two evenly, scooping it into the prepared tins. Bake for 40 minutes or until lightly golden on top and the centre is done. Cool in the tin.

Blend the almonds, shortbread, sugar and butter together in a food processor. Spread out and bake on a large parchment lined tray at 180C/350F for 10 minutes. Turn the mixture for even browning and return to the oven for another 5-8 minutes until toasted and crunchy. Cool completely and break into tiny pieces.

Place egg yolks, sugar, butter and lemon juice in a microwave proof bowl. Heat on high for around 4-5 minutes, whisking in between until bubbles form. Pass through a sieve and cool completely.

In a pot, combine sugar and water and bring to a boil. Slice the lemon thinly and add to the syrup. Simmer for 10 minutes until slices are translucent. Drain and cool.

Chill mixer bowl for 10 minutes. Whip cream, icing sugar, and vanilla bean paste until fluffy.

Slice each cake in half and layer with syrup, lemon zest, cream, and lemon curd. Spread cream on the sides and top of the cake, smooth with a scraper. Add almond crunch and candied lemons on top.