Ensure you use fresh, high-quality ingredients. This includes fresh plums, good quality flour, baking powder, butter, eggs, sugar, and spices like cinnamon and nutmeg for flavor.
Soak the chopped plums (and any other dried fruits if you're using them) in rum or brandy a day or two in advance. This helps infuse the fruits with flavor and keeps them moist.
Line the cake pan with parchment paper or grease it well with butter and dust with flour to prevent sticking. This will ensure the cake comes out easily without breaking.
Cream the butter and sugar properly until light and fluffy. This step aerates the mixture and creates a light texture in the cake.
Sift the dry ingredients (flour, baking powder, spices) together before adding them to the wet ingredients. This ensures an even distribution of leavening agents and spices, resulting in a well-risen and flavorful cake.
When adding the dry ingredients to the wet mixture, fold gently using a spatula. Overmixing can lead to a dense cake, so be gentle and mix until just combined.
Drain the soaked fruits and coat them lightly with flour before adding them to the cake batter. This prevents them from sinking to the bottom of the cake during baking.
Preheat your oven to the specified temperature and place the cake on the middle rack. Follow the recommended baking time, but start checking a few minutes before the timer goes off to avoid over-baking.