Preheat the oven to 180 degrees (convection 160 degrees). Grease a small springform pan (20 centimeters in diameter) with a tablespoon of butter and sprinkle with two tablespoons of almonds.
Separate eggs. Beat egg whites with a pinch of salt until stiff. Stir in 50 g of sugar and continue beating for about a minute. Mix the remaining butter, 75 g sugar and orange peel until very creamy. Add egg yolks and stir in for a minute. Mix the flour, the remaining almonds and baking powder and stir in portions alternately with the orange juice into the butter and egg mixture. Fold in the egg whites and pour the batter into the springform pan.
Bake in the middle of the hot oven for about 30 minutes (test with wooden sticks). After baking, let it cool down in the tin for 10 minutes, then turn it out onto a wire rack and sprinkle with icing sugar.