Ginger powder is perfect for baking, it tastes spicier than fresh, goes well with cardamom and cinnamon, gives baked goods a pleasant tart aroma and a slightly burning spicy taste.
Preheat oven to 160°C. Line a baking sheet with baking paper. Chop the nuts in a blender. In a large bowl, combine flour, cocoa, ginger, cardamom and ground nuts.
In a separate bowl, beat the eggs with sugar into a fluffy foam, the volume of the mass should increase several times. Pour in the rum. Gently fold the nut-flour mixture into the egg mixture in several batches, mixing with a spatula in a “folding” motion each time to keep the mass airy.
Spread the batter on a baking sheet in a layer about 1.5 cm thick, flatten lightly with a spatula and bake until done, about 30 minutes. Cool the finished cake, sprinkle with powdered sugar and cut into small squares.