Preheat the oven to 375 degrees F. Grease a 26cm spring form pan with butter and set aside. In a small bowl, sieve together the spelt flour, corn starch and baking powder. Set aside.

Separate the egg yolks and whites, putting the egg yolks into a large bowl or the bowl of a stand mixer, and the egg whites into a small bowl. Using a hand held beater or the whisk attachment on a stand mixer, whisk the egg yolks with the warm water until frothy, then add 2/3 of the sugar and the vanilla extract and whisk on high until the mixture is thick, creamy and the sugar is dissolved. If using a stand mixer, transfer this egg yolk mixture to a large bowl and set aside.

Clean and dry the stand mixer bowl and whisk attachment, then place the egg whites into it. Whisk the egg whites and the remaining sugar on high until stiff peaks form and the mark of a small paring knife sliced into the egg whites is retained. Gently empty the egg whites on top of the egg yolk mixture, then pour the flour mixture on top. Gently fold together using a large spatula until combined. Pour into the greased spring form pan and spread evenly. Bake for 25-30 minutes or until a toothpick inserted in the centre comes out clean.

Remove from the oven and place on a wire rack to cool for 30 minutes before removing the spring form pan and allowing to cool completely.

While waiting for the cake to cool, place a sieve over a medium bowl and set aside. Pour 375ml of the milk and the vanilla extract into a large saucepan. Cook over high heat, stirring often until it comes to a simmer, then remove from the heat.

In a small bowl, whisk the remaining milk, egg yolks, sugar and cornstarch together until combined. While whisking quickly, slowly pour the hot milk mixture into the egg yolk mixture in a steady stream. Return the entire mixture to the saucepan and cook over high heat, whisking constantly, until it has come to a boil and thickened.

Pour the finished pastry cream into the sieve and using the whisk, stir until it has all been passed through (this step eliminates having little pieces of cooked egg white and/or yolk in your buttercream and should not be skipped). Place a piece of plastic wrap directly on top of the pastry cream and allow to cool at room temperature for an hour then place in the fridge for a minimum of 1 hour to set.

Remove the pastry cream and allow to come to room temperature. It is very important for this next step that both the butter and the pastry cream are at the same temperature.

In a large bowl with a hand held mixer or in the bowl of a stand mixer with the paddle attachment, beat the butter on high until pale and fluffy (approximately 3 minutes). Scrape down the sides of the bowl and on medium speed add the pastry cream 1 tbsp at a time, incorporating well between each addition.

Using a large, serrated bread knife cut the cake into three equal layers. Place the bottom layer on a cake plate or platter and gently spread the jam on top. Spread 1/4 of the buttercream on top of the jam. Place the second layer on top and spread with just over 1/4 of the remaining buttercream. Place the third layer on top. Reserve 3/4 - 1 cup of the buttercream for decoration, then spread the rest of the buttercream on the sides and top of the cake.

Place some almonds on a dough scraper, then lift and press them onto the sides of the cake. Pipe 12 swirls on top of the cake with the reserved buttercream. Slice 6 strawberries in half and place on the swirls with the inside of each strawberry facing up. Slice additional strawberries in thin slices lengthwise and arrange in concentric circles in the middle of the cake. Sprinkle the remaining sliced almonds in the gaps between the buttercream swirls and the strawberries in the middle. Chill for at least one hour before serving.