For the moist almond cake, separate the eggs and beat the egg whites with a pinch of salt until stiff. Stir in 50g sugar and continue beating for about 1 minute.
Cream butter with 75g sugar and orange zest. Add egg yolks and mix for one minute. Mix flour with almonds and baking powder and stir into the butter-egg mixture in batches, alternating with the orange juice. Carefully fold in the beaten egg white.
Pour the batter into a greased small springform pan and bake in a preheated oven at 180° for about 30 minutes. Remove from the oven and let cool completely. Serve the moist almond cake sprinkled with powdered sugar.