Preheat the oven to 375 degrees F and line a 26cm spring form pan with parchment paper. Set aside.
In the bowl of a stand mixer or in a large bowl with a hand mixer, whisk together the egg yolks and 2 tbsp of water together until foamy. Add approximately two-thirds of the sugar and vanilla extract and whip until the sugar has melted and the mixture is very creamy.
In another bowl beat the egg whites until very stiff. Add the remaining one-third of sugar and beat again until combined. Set aside. In a small bowl, sift together the spelt flour, tapioca flour and baking powder. Gently pour the egg white mixture on top of the egg yolk mixture and then add the flour mixture on top of the egg white mixture. Gently fold until just combined.
Pour the mixture into the spring form pan and spread evenly. Bake for 20 - 30 minutes or until golden brown. Remove from the oven and let cool on a wire rack before removing from the spring form pan. To remove from the spring form pan run a small, sharp knife around the perimeter before unlocking the sides of the pan. Flip upside down and remove parchment paper.
In a small bowl mix the gelatine and water with a whisk. Set aside for a few minutes until it starts to swell and thicken. Using a double boiler or small pot with a little water under the bowl, melt and mix the gelatine on medium/low heat until clear. Set aside to cool until it is no longer hot, but still liquid.
In a medium bowl mix the yogurt, milk, sugar, vanilla extract and lemon juice until combined. Add the warm gelatine in a small stream while mixing and mix until well blended. Chill in the fridge to thicken. In a medium bowl whip the whipping cream until stiff peaks. Put the bowl in the fridge to keep cool.
Wash and drain the strawberries. Reserve 12 strawberries for decoration. Cut the remaining strawberries in half or quarters (for larger berries). Once the yogurt mixture thickens to a pudding consistency, remove it from the fridge and fold in the strawberries and whipped cream.
Cut the completely cooled cake into two thin layers. I find this is easiest using a long bread cutting knife and turning the cake as I go. Place the bottom layer on a serving plate or other serving dish. Place and close the springform ring around the bottom layer. Gently pour the strawberry yogurt mixture on top of the bottom layer and spread gently and evenly. Place the top cake layer on top. Chill in the fridge until well set (a couple hours).
Slide a small, sharp knife around the cake to release the springform ring from the cake. Dust the cake with icing sugar, shaved chocolate and the 12 reserved strawberries cut in half.