1. Mix together the ingredients in Group A (boiling water, oats, and baking soda) and set aside for a few minutes to allow the oats to soften.

2. In a separate bowl, cream together the ingredients in Group B (margarine, eggs, sugar, and vanilla) until the mixture is smooth and well combined.

3. In another bowl, combine the ingredients in Group C (flour, baking powder, cocoa, and salt) and mix well.

4. Now, it’s time to bring all three mixtures together. Gradually add the Group A mixture to the creamed Group B mixture, stirring gently until they are just mixed.

5. Next, gradually add the Group C mixture to the combined Group A and B mixture. Continue mixing until all the ingredients are fully incorporated.

6. Grease a tube or bundt pan and pour the cake batter into it, ensuring it is evenly distributed.

7. Preheat your oven to 180°C/350°F and bake the cake for approximately 50 minutes, or until fully cooked. To check if the cake is done, insert a toothpick into the thickest part. If it comes out clean, the cake is ready to be removed from the oven. If there is still batter on the toothpick, leave it in a bit longer and check periodically.

8. Once the cake is fully cooked, remove it from the oven and allow it to cool completely in the pan before removing it and transferring it to a serving plate.

9. To add a final touch, you can decorate the cake with a dusting of powdered sugar, a drizzle of chocolate ganache, or your favourite frosting.