1. Preheat your oven to 350°F or 180°C.

2. In a large mixing bowl, whisk together 1 cup (200g) of sugar, 3 large egg whites, and 1 1/2 cups (190g) of ground almonds until stiff peaks form.

3. Spread the mixture onto a parchment-lined baking sheet and bake for 20-25 minutes, or until lightly golden.

4. Allow the base to cool completely on the baking sheet.

5. In another large mixing bowl, beat 1 cup (225g) of softened butter until light and fluffy.

6. Gradually add 2 cups (475ml) of heavy cream, beating until stiff peaks form.

7. In a separate bowl, whisk together 3 large egg yolks and 1 cup (200g) of sugar until pale and thick.

8. Slowly pour the egg yolk mixture into the butter mixture, beating continuously until smooth and creamy.

9. Place the cooled almond base on a serving plate.

10. Spread a layer of buttercream frosting on top of the base, followed by another layer of almond base.

11. Repeat this process until all the ingredients are used, finishing with a layer of buttercream frosting on top.

12. Decorate as desired and serve.