Instructions:

1. For the sponge cake prepare the batter.

2. Preheat the oven to 180°C (350°F) and grease an 18 cm (7-inch) round cake pan.

3. In a bowl, beat the whole eggs with sugar until fluffy.

4. Gently fold in the flour mixed with cocoa powder.

5. Pour the batter into the prepared cake pan and bake for about 20-25 minutes, or until a toothpick comes out clean.

6. Let the sponge cake cool completely. Once cooled, cut it into three layers.

7. For the Rum Walnut Cream: in a mixing bowl, beat the butter or margarine with powdered sugar until creamy. Prepare a thick pudding by cooking the milk with the puding powder. Allow it to cool.

8. Add the cooled pudding to the butter-sugar mixture, along with the ground walnuts, rum (or rum essence), and lemon zest. Beat everything together until the mixture is light and fluffy.

9. Once the mixture is thickened, pour it over the top of the cake, allowing it to drip down the sides.

10. Place the bottom layer of sponge on a serving plate and spread a generous amount of walnut cream over it.

11. Repeat for the other layers, and cover the sides of the cake with the cream as well.

12. For the Chocolate Glaze: in a small saucepan, melt the butter or margarine with powdered sugar and cocoa powder. Add a little milk and cook for 1-2 minutes until the glaze thickens.

13. After assembling, pour the chocolate glaze over the top, letting it flow down the sides.

14. Decorate the top of the cake with the walnut halves.